JP2022082142A - Shield machine - Google Patents

Abstract

To provide a structure that efficiently prevents damage to a sealing member due to earth and sand in a shield machine in a space-saving manner.SOLUTION: The inventive shield machine comprises: a cutter chamber 4 formed in a tubular skin plate 3 and accommodating earth and sand excavated by a cutter head 2: an annular cutter drive body 8 that is installed facing the cutter chamber 4, has its outer periphery provided with a sealing material 14, which seals a gap with the skin plate 3 opened in the traveling direction to prevent the intrusion of earth and sand from the cutter chamber 4, and is rotated in the circumferential direction by a cutter motor 13 to rotate the cutter head 2; a first protrusion 15 provided continuously in the circumferential direction in front of the sealing material 14 in the cutter drive body 8; and a second protrusion 16 provided in front of the first protrusion 15 on the skin plate 3 so as to overlap the first protrusion 15 in the axial direction of the skin plate 3.SELECTED DRAWING: Figure 2

Description

The present invention relates to a shield excavator, and more particularly to a technique for protecting a cutter drive body that rotates a cutter head from earth and sand.

By rotating the cutter head on the front, the shield excavator excavates the earth and sand of the ground (face) in front by the bit placed on the cutter head, and the segment carried from the outside is excavated inside the excavation pit. It is a device that forms a tunnel by assembling it around the circumference. In addition, by taking the excavated earth and sand into the cutter chamber from the earth and sand intake port of the cutter head, the earth pressure of the face is counteracted and the collapse of the face is prevented.

A partition wall is provided on the wellhead side (opposite side of the cutter head) of the cutter chamber, and the excavated earth and sand is taken into the mud drain pipe by a screw conveyor or the like from the soil discharge opening installed below the partition wall. It is carried to the outside of the tunnel and discharged.

An elector for assembling the segment is provided at the rear of the shield excavator, and the segment carried in from the starting shaft is assembled in a ring shape so as to be the lining of the tunnel. In addition, a shield jack is provided at the rear of the shield excavator, and by extending the shield jack and pushing the front surface of each segment (the cut surface on the face side of the tunnel lining), the shield excavator advances. do.

The cutter head rotates while being pressed against the face, so that the face is cut down and earth and sand are taken into the cutter chamber from the intake port as described above. At this time, since the pressure is applied toward the front (face), the excavated earth and sand easily invade the gap between the devices in this direction. Furthermore, in the case of muddy water type shield work or muddy soil pressure shield work, water is added to the face to increase the fluidity of the earth and sand, so that the earth and sand intrudes even through a small gap in the equipment.

The shield excavator is a cutter drive that transmits the power of the cutter head, the motor that rotates it, and the power of the motor to the fixed parts such as the skin plate that constitutes the outer circumference of the main body and various equipment connected to it. There is a part that rotates like a body. The fixed portion and the rotating portion are structurally separated, and the rotating portion is supported by the fixed portion via a gearbox, a bearing, or the like.

If the earth and sand in the cutter chamber reaches the inside of the cutter drive body (gearbox, bearing, etc.) through the gap between the rotating part of the fixed part and the separated part, the drive of the cutter head will be hindered. .. In that case, it is necessary to dismantle the shield excavator and replace the cutter drive body, which is very time-consuming and time-consuming.

Especially when the total length of the tunnel is long, the shield excavator will excavate the ground of various soils. Then, when excavating the gravel ground, the crushed debris of the gravel is taken in, and the sealing material (sealing member) that seals between the fixed portion and the rotating portion is easily damaged. If the sealing material is damaged, earth and sand easily enter the gearbox, bearings, and the like, increasing the risk that the cutter head cannot be driven.

Therefore, as a technique for preventing the intrusion of earth and sand into such a gap, an unevenness (labyrinth: labyrinth) is provided on the outside of the sealing material to prevent the intrusion of earth and sand. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 55-076297), a labyrinth member is attached to the entire inner circumference of the tip of the shield frame so as to protrude from the tip of the shield frame (skin plate). It is disclosed that a gap leading to a cutter seal (sealing material) is formed between an outer surface and an inner surface of an outer peripheral portion of a cutter frame (cutter head). Further, in Patent Document 2 (Actual Kaihei 04-030192), a seal in which a plurality of sealing members (sealing materials) are arranged between the machine body casing (skin plate) and the outer peripheral surface of the rotary cutter (cutter head). It is disclosed that a labyrinth seal structure portion is provided in front of the first stage of the apparatus, and fresh water having a pressure higher than the muddy water pressure is injected into the labyrinth seal structure portion to prevent the intrusion of muddy water.

Jitsukaisho 55-07627 Jikkenhei 04-030192 Gazette

However, in the technique of providing unevenness on the outside of the sealing material (sealing member) as described in Patent Documents 1 and 2, a space for installing the unevenness on the outside of the sealing material is required. Further, the more unevenness is, the more effective it is to prevent the invasion of earth and sand, but for that purpose, not only a large space is required on the outside of the sealing material, but also the structure becomes complicated.

In particular, when the diameter of the shield excavator is small (for example, 2500 mm or less), the motor, gearbox, bearing, and the like are arranged near the inner wall of the skin plate, so that the space that can be secured for installing the unevenness is limited.

The present invention has been made from the above-mentioned technical background, and an object of the present invention is to provide a shield excavator capable of efficiently preventing damage to a sealing member due to earth and sand in a space-saving manner.

In order to solve the above problems, the shield excavator of the present invention according to claim 1 has a tubular skin plate in which a cutter head for excavating the ground is installed at the tip in the traveling direction, and the cutter head in the skin plate. A cutter chamber formed on the back side and accommodating earth and sand excavated by the cutter head, a partition wall separating the cutter chamber and the inside of the skin plate, and a partition wall installed facing the cutter chamber and opening in the traveling direction. An annular cutter that seals the gap between the skin plate and the cutter chamber to prevent the intrusion of earth and sand from the cutter chamber is attached to the outer periphery, and is rotated in the circumferential direction by a drive source to rotate the cutter head. The drive body, the first protrusion provided continuously in the circumferential direction in front of the sealing member in the cutter drive body, and the first protrusion in the axial direction of the skin plate are overlapped with each other. It is characterized by having a second protrusion provided at a predetermined interval in front of the first protrusion in the skin plate.

The shield excavator of the present invention according to claim 2 is characterized in that, in the invention according to claim 1, the second protrusion is continuously provided on the inner circumference of the skin plate. do.

In the shield excavator of the present invention according to claim 3, in the invention according to claim 1 or 2, an intake port is provided with an opening in the partition wall, and earth and sand in the cutter chamber is taken from the intake port. It further has a mud draining means for taking in and discharging to the outside of the machine, and the taking-in port is formed inside the cutter drive body in the radial direction.

The shield excavator of the present invention according to claim 4 has a support cylinder located on the inner peripheral side of the cutter drive body and the cutter drive body in the invention according to any one of claims 1 to 3. It is characterized by further having a sealing member which is attached to the inner circumference of the cylinder and seals a gap with the support cylinder to prevent the intrusion of earth and sand from the cutter chamber.

In the invention according to claim 4, the shield excavator of the present invention according to claim 5 has the number of stages of the sealing member attached to the outer periphery of the cutter drive body along the axial direction of the skin plate. It is characterized in that the number of stages of the sealing member attached to the inner circumference of the cutter drive body is larger than the number of stages along the axial direction of the skin plate.

The shield excavator of the present invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the shield excavator is predetermined to the face with earth and sand in the cutter chamber which has become muddy. It is a mud pressure shield excavator that excavates the ground while applying the pressure of.

According to the present invention, the pressure at which the earth and sand in the cutter chamber is about to enter is received by the second protrusion, and the intrusion of the earth and sand that damages the sealing member can be prevented by the first protrusion. can. Further, there is no need for a space for providing a structure for preventing the intrusion of earth and sand on the outside of the sealing member. Therefore, it is possible to efficiently prevent damage to the sealing member due to earth and sand in a space-saving manner.

It is a schematic block diagram which shows the inside of the shield excavator of one Embodiment of this invention through from the side. FIG. 3 is an enlarged cross-sectional view showing the upper part of the cutter drive body in the shield excavator of FIG. 1. FIG. 3 is an enlarged sectional view showing a lower portion of a cutter drive body in the shield excavator of FIG. 1.

Hereinafter, embodiments as an example of the present invention will be described in detail with reference to the drawings. In the drawings for explaining the embodiments, the same components are designated by the same reference numerals in principle, and the repeated description thereof will be omitted.

The structure of the shield excavator according to this embodiment will be described with reference to FIGS. 1 to 3.

FIG. 1 is a schematic configuration diagram showing the inside of the shield excavator according to the embodiment of the present invention from the side surface, and FIG. 2 is a sectional view showing an enlarged upper portion of a cutter drive body in the shield excavator of FIG. FIG. 3 is an enlarged cross-sectional view showing the lower part of the cutter drive body in the shield excavator of FIG.

In FIG. 1, in the shield excavator 1 of the present embodiment, for example, the cutter chamber 4 formed between the cutter head 2 and the skin plate 3 (specifically, the hood portion of the skin plate 3) is filled with mud. It is a mud pressure shield excavator that generates mud pressure by excavating in this state and excavates in a state where the mud pressure opposes the earth pressure of the face. The mud in the cutter chamber 4 is generated by injecting an additive into the earth and sand excavated by the cutter head 2 and kneading it, and is impermeable and plastically fluid (property that can be freely deformed and moved). And have.

The operation of the shield excavator 1 is controlled by an operator in the driver's cab in the following carriage (not shown) arranged behind the shield excavator 1. Further, the overall operation of the shield excavator 1 is controlled by the control unit provided in the driver's cab.

The tunnel constructed by the shield excavator 1 is not particularly limited, but is, for example, a tunnel having a relatively small diameter such as a water supply tunnel, a sewage tunnel, or a cable tunnel. Therefore, the shield excavator 1 of the present embodiment has a relatively small outer diameter of, for example, about 1970 mm.

The cutter head 2 constituting the shield excavator 1 is a member for excavating the face (ground) of the ground, and is supported by the bearing 2-1 attached to the partition wall 7 described later, and is the tip of the skin plate 3 in the traveling direction. The skin plate 3 is installed so as to be rotatable in the forward and reverse directions along the circumferential direction of the skin plate 3.

The type of the cutter head 2 is, for example, a disk-shaped spoke type. That is, a central hub portion 2a, a plurality of spoke portions 2b extending radially from the hub portion 2a toward the outer periphery, an annular outer peripheral ring portion 2c connecting between the tip portions of the spoke portions 2b, and these members. It has an opening (not shown) formed between them.

Bits 5a for excavating the ground are installed on the front surface (the surface facing the face) of the hub portion 2a, the spoke portions 2b, and the outer peripheral ring portion 2c. Further, the hub portion 2a and the spoke portion 2b are provided with a mud material discharge port (not shown). This mud material discharge port is a portion for discharging a mud material (mud-making soil material) such as bentonite toward the face. As the mud material, for example, a foam material may be used instead of bentonite, or both bentonite and the foam material may be used. Further, a copy cutter 5b is installed on the outer peripheral ring portion 2c. The copy cutter 5b has a role of performing extra digging at the time of constructing a sharp curve, controlling the attitude of the shield excavator 1, and the like.

The back surface of the cutter head 2 has a function of connecting the cutter drive body 8 and the cutter head 2, which will be described later, and stirring and mixing the earth and sand in the cutter chamber 4 and the mud material when the cutter head 2 rotates. The rod-shaped connecting arm 6 is provided so as to extend in the axial direction of the skin plate 3. In the present embodiment, the number of connecting arms 6 is 6, but the number of connecting arms 6 can be freely set.

As shown in the figure, the skin plate 3 constituting the shield excavator 1 includes a front body plate 3a, a rear body plate 3b behind the front body plate 3a, and a tail seal 3c behind the front body plate 3b.

The front body plate 3a and the rear body plate 3b are formed in a cylindrical shape, for example, by a cylindrical steel plate, and form the outer shape of the skin plate 3 and form a hollow space inside the skin plate 3. be. The front body plate 3a and the rear body plate 3b are engaged by entering in a state where the spherical bearing portion at the tip of the rear body plate 3b is in contact with the inner peripheral surface of the front body plate 3a on the rear end side of the front body plate 3a. Has been done.

The tail seal 3c is a sealing member that prevents groundwater and the like from entering the skin plate 3 from the rear of the skin plate 3 during excavation work, and is an inner circumference of the rear body plate 3b at the rear end of the rear body plate 3b. It is installed in a frame shape along the line.

On the front surface side of the front body plate 3a, a partition wall 7 that divides the hollow space in the skin plate 3 into the face side and the inside of the machine is installed at a position retracted inward from the front surface of the skin plate 3. A manchatch (a passage for an operator to enter the cutter chamber 4) is formed in the partition wall 7, and the cutter chamber 4 described above is formed in the hood portion of the skin plate 3 on the face side of the partition wall 7. It is provided. The earth and sand excavated by the cutter head 2 are taken into the cutter chamber 4 through the opening of the cutter head 2.

The cutter drive body 8 is installed facing the cutter chamber 4 of the shield excavator 1. Further, a cutter motor (drive source) 13, a soil pressure gauge 12, and the like are attached to the partition wall 7, and inside the partition wall 7, a center-folding jack 9a, a shield jack 9b, a mud drain pipe (mud draining means) 10, and an elector are attached. 11 and the like are installed.

The cutter drive body 8 is an annular structure that rotates in the circumferential direction, is driven by the cutter motor 13, and rotates the cutter head 2 in the forward and reverse directions via the connecting arm 6.

As described above, the shield excavator 1 of the present embodiment has a relatively small diameter, and a bearing 2-1 for supporting the cutter head 2 is arranged at the center of the shield excavator 1 in the radial direction, and a bearing 2-1 is arranged around the shield excavator 1. An earth pressure gauge 12, an injection hole for a chemical solution (not shown), a man hatch of a partition wall 7, and the like are arranged. Therefore, the cutter drive body 8 for rotating the cutter head 2 is provided along the radial outer side of these components, that is, along the inner circumference of the skin plate 3.

The cutter drive body 8 is rotatably installed between the gearbox 7a on the outer peripheral side fixed to the partition wall 7 and the support cylinder 7b on the inner peripheral side. As shown in FIGS. 2 and 3, the cutter drive body 8 meshes with the external gear 13a attached to the output shaft of the cutter motor 13 and is supported by the gearbox 7a via the bearing 8aa. And an annular rotational force transmitting portion 8b fixed to the cutter head 2 side of the internal gear portion 8a and located between the skin plate 3 and the support cylinder 7b. Further, the above-mentioned connecting arm 6 is attached to the rotational force transmission unit 8b.

Here, in FIGS. 2 and 3, the outer periphery of the rotational force transmission unit 8b is sealed between the rotational force transmission unit 8b and the skin plate 3 from the cutter chamber 4 to the inside (that is, a rotation mechanism). A sealing material (sealing member) 14 for preventing the intrusion of earth and sand (to the gearbox 7a and the bearing 8aa) is provided so as to be pressed against the skin plate 3. In addition, a sealing material (sealing member) that also seals the inner circumference of the rotational force transmission unit 8b between the rotational force transmission unit 8b and the support cylinder 7b to prevent sediment from entering the inside from the cutter chamber 4. ) 14 is provided so as to be pressed against the support cylinder 7b.

These sealing materials 14 are made of rubber, for example, and as shown in the figure, the skin plate 3 has four annular sealing pieces 14a provided along the axial direction of the skin plate 3 in a state of being inclined toward the front. And the support cylinder 7b are pressed against each other by elastic force.

The sealing material 14 provided on the outer periphery of the rotational force transmission unit 8b is provided in two stages along the axial direction of the skin plate 3, and the sealing material 14 provided on the inner circumference of the rotational force transmission unit 8b is the skin plate 3. It is provided in one step along the axial direction. This is because more earth and sand accumulates on the bottom surface of the cutter chamber 4, so that the rotational force is transmitted more than the earth and sand that invades from the inner circumference of the rotational force transmission unit 8b (that is, between the rotational force transmission unit 8b and the support cylinder 7b). This is because the amount of earth and sand that invades the inside from the outer periphery of the portion 8b (that is, between the rotational force transmitting portion 8b and the skin plate 3) is larger.

However, the number of stages of the sealing material 14 provided on the outer periphery of the rotational force transmission unit 8b and the number of stages of the sealing material 14 provided on the inner circumference of the rotational force transmission unit 8b are not particularly limited, and the number of stages of the former is not particularly limited. It does not have to be more than the latter number of stages.

By the way, the sealing material 14 prevents the earth and sand in the cutter chamber 4 of the shield excavator 1 from invading the inside of the cutter drive body 8, but when the earth and sand such as crushed gravel are taken in. , The sealing material 14 itself is damaged and the sealing function is impaired. Then, the debris enters the gearbox 7a and the bearing 8aa, and as a result, the driving of the cutter head 2 is hindered.

Therefore, in order to prevent the sealing material 14 from being damaged by such earth and sand, the shield excavator 1 of the present embodiment is provided with a first protrusion 15 on the cutter drive body 8 and is included in the skin plate 3. A second protrusion 16 is provided on the periphery. The details of the first protrusion 15 and the second protrusion 16 will be described later.

A V-ring 17 for sealing between the rotational force transmission portion 8b and the skin plate 3 is provided behind the sealing material 14 provided on the outer periphery of the rotational force transmission portion 8b. Further, a V ring 17 for sealing between the rotational force transmission portion 8b and the support cylinder 7b is also provided behind the sealing material 14 provided on the inner circumference of the rotational force transmission portion 8b. These V-rings 17 are made of rubber, for example, and the sealing material 14 located on the inner circumference of the rotational force transmitting portion 8b has two stages.

The center-folding jack 9a is a device that connects the front body plate 3a and the rear body plate 3b and corrects the propulsion direction and posture of the shield excavator 1. A plurality of center-folded jacks 9a are arranged side by side along the circumferential direction of the skin plate 3 so as to straddle the boundary between the front body plate 3a and the rear body plate 3b in the skin plate 3.

By supplying pressure oil to the center-folded jack 9a and propelling the shield excavator 1 in a state where the front body plate 3a and the rear body plate 3b are bent in a predetermined direction and angle, the shield excavator 1 It is possible to control the propulsion direction and attitude.

The shield jack 9b is a device that generates a propulsive force for advancing the shield excavator 1 by taking a reaction force on the segment SG installed behind the skin plate 3. A plurality of shield jacks 9b are arranged side by side along the circumferential direction of the skin plate 3 so as to straddle the boundary between the front body plate 3a and the rear body plate 3b in the skin plate 3.

The segment SG is a member that covers the inner circumference of the drilling pit, and a plurality of segments SG are installed along the circumferential direction of the drilling pit. The segment SG is composed of, for example, a steel box-shaped segment or a concrete segment. The width (dimension along the longitudinal direction of the excavation pit) of the segment SG is, for example, about 1000 mm, and the height (thickness) is, for example, about 75 mm.

The mud drain pipe 10 is a device for discharging the earth and sand in the cutter chamber 4 to the outside of the machine. In the mud drain pipe 10, a screw conveyor 10a that takes in the earth and sand in the cutter chamber 4 into the pipe and sends it to the outside of the machine is arranged. The screw conveyor 10a is a take-in inner portion 10 arranged at a position slightly higher than the center in the height direction of the skin plate 3 behind the skin plate 3 from the earth and sand take-in port 10-1 provided by opening in the partition wall 7. It is provided in a state of being continuously extended diagonally upward toward -2.

The intake port 10-1 of the mud drain pipe 10 is formed on the inner side in the radial direction of the cutter drive body 8 described above. This is because, as described above, in the shield excavator 1 of the present embodiment having a relatively small diameter, the cutter drive body 8 is provided along the inner circumference of the skin plate 3, so that the intake port 10 is provided. This is because -1 cannot be formed close to the inner circumference of the skin plate 3.

The Elekta 11 is an assembly device that grips the segment SG, turns in the inner peripheral direction of the drilling pit, and transfers it to the assembly position in the inner peripheral direction of the drilling pit. The Elekta 11 is installed in the rear body plate 3b in a state of being rotatable along the circumferential direction of the excavation pit by a hydraulic motor (not shown) for driving the Elekta.

The soil pressure gauge 12 is a sensor that detects the mud pressure in the cutter chamber 4. The shield excavator 1 performs excavation work while maintaining the stability of the face by managing the mud pressure in the cutter chamber 4 detected by the earth pressure gauge 12.

Here, as described above, in order to prevent damage to the sealing material 14 due to the intrusion of earth and sand (particularly earth and sand such as crushed gravel) in the cutter chamber 4, the first protrusion on the cutter drive body 8 is provided. 15 is provided, and a second protrusion 16 is provided on the inner circumference of the skin plate 3.

That is, as shown in detail in FIGS. 2 and 3, in the cutter drive body 8, the first protrusion 15 is continuously provided in the circumferential direction in front of the sealing material 14 provided on the outer periphery of the cutter drive body 8. It is provided. Further, on the inner circumference of the skin plate 3, the first protrusion 15 is overlapped with the first protrusion 15 in the axial direction of the skin plate 3, and the first protrusion 15 is designated in front of the first protrusion 15. The second protrusions 16 are continuously provided at intervals.

Here, since the gap between the rotational force transmission portion 8b and the skin plate 3 opens in the traveling direction of the shield excavator 1, the present inventor presents the pressure in the cutter chamber 4 due to the forward pressure of the shield excavator 1. Considering that the earth and sand enter through the opening, it was examined whether the earth and sand could be prevented from reaching the sealing material 14 only by the first protrusion 15 without providing the second protrusion 16.

However, in this structure, the inner wall of the first protrusion 15 and the skin plate 3 around it is worn, and it is not possible to sufficiently prevent the inflow of earth and sand. This is because the first protrusion 15 provided on the cutter drive body 8 rotates, so that the earth and sand pushed into the gap between the first protrusion 15 and the inner wall of the skin plate 3 is the cutter drive body 8. It is considered that the cause is that the first protrusion 15 and the skin plate 3 are worn by being rubbed against the skin plate 3 by the rotation. In particular, the earth and sand that has entered between the first protrusion 15 and the skin plate 3 is sandwiched between the two so that there is no escape, which is also considered to be one of the factors that promoted the wear.

Therefore, in addition to the first protrusion 15, the skin plate 3 is provided with the second protrusion 16 described above. The second protrusion 16 does not rotate because it is installed on the skin plate 3 side. Further, since it is on the face side of the cutter drive body 8, the earth and sand will not be caught between the second protrusion 16 and other members. Therefore, it is possible to receive the pressure that the earth and sand in the cutter chamber 4 tries to invade by the second protrusion 16 and prevent the invasion of the earth and sand that damages the sealing material 14 by the first protrusion 15. become.

Since the first protrusion 15 and the second protrusion 16 are installed in the axial direction of the skin plate 3 with respect to the sealing material 14, a structure for preventing the intrusion of earth and sand to the outside of the sealing material 14 is provided. No space is required to provide it. Therefore, it is possible to efficiently prevent the intrusion of earth and sand that damages the sealing material 14 in a space-saving manner.

Although the invention made by the present inventor has been specifically described above based on the embodiments, the embodiments disclosed in the present specification are exemplary in all respects and are limited to the disclosed techniques. is not. That is, the technical scope of the present invention is not limitedly interpreted based on the description in the above-described embodiment, but should be interpreted according to the description of the scope of claims, and the scope of claims. All changes are included as long as they do not deviate from the description technology and the equivalent technology and the gist of the claims.

For example, in the above-described embodiment, the second protrusion 16 is continuously provided on the inner circumference of the skin plate 3, but it is sufficient if the second protrusion 16 is provided at least on the lower half of the skin plate 3. This is because it is considered that there is relatively little earth and sand in the upper half of the cutter chamber 4. However, since the earth and sand in the cutter chamber 4 are rotationally agitated by the connecting arm 6, it is desirable that the second protrusion 16 is continuously provided on the inner circumference of the skin plate 3.

In the above description, the case where the present invention is applied to a shield excavator with mud pressure has been described, but the present invention is not limited to this, and is also applied to other shield excavators such as a muddy water type shield excavator. To.

1 Shield excavator 2 Cutter head 2-1 Bearing 3 Skin plate 3a Front body plate 3b Rear body plate 3c Tail seal 4 Cutter chamber 5a Bit 6 Connecting arm 7 Partition 7a Gearbox 7b Support cylinder 8 Cutter drive body 8a Internal gear part 8aa Bearing 8b Rotational force transmission part 9a Mid-bending jack 9b Shield jack 10 Mud drain pipe (mud drain means)
10-1 Intake port 10-2 Intake depth 10a Screw conveyor 11 Electa 12 Soil pressure gauge 13 Cutter motor (drive source)
13a External gear 14 Sealing material (sealing member)
14a Circular seal piece 15 First protrusion 16 Second protrusion 17 V-ring SG segment

Claims (6)

A cylindrical skin plate with a cutter head for excavating the ground installed at the tip in the direction of travel,
A cutter chamber formed on the back surface side of the cutter head in the skin plate and accommodating earth and sand excavated by the cutter head.
A partition wall separating the cutter chamber and the inside of the skin plate,
A sealing member installed facing the cutter chamber and sealing the gap with the skin plate opened in the traveling direction to prevent the intrusion of earth and sand from the cutter chamber is attached to the outer periphery, and is rotated by a drive source. An annular cutter drive body that rotates in a direction to rotate the cutter head,
A first protrusion provided continuously in the circumferential direction in front of the sealing member in the cutter drive body, and
A second protrusion provided at a predetermined distance in front of the first protrusion on the skin plate so as to overlap the first protrusion in the axial direction of the skin plate.
A shield excavator characterized by having. The second protrusion is continuously provided on the inner circumference of the skin plate.
The shield excavator according to claim 1. The intake port is provided by opening in the partition wall, and further has a mud draining means for taking in the earth and sand in the cutter chamber from the intake port and discharging it to the outside of the machine.
The intake port is formed inside the cutter drive body in the radial direction.
The shield excavator according to claim 1 or 2, characterized in that. A support cylinder located on the inner peripheral side of the cutter drive body and
A sealing member attached to the inner circumference of the cutter drive body and sealing a gap with the support cylinder to prevent sediment from entering from the cutter chamber.
The shield excavator according to any one of claims 1 to 3, further comprising. The number of stages of the sealing member attached to the outer periphery of the cutter drive body along the axial direction of the skin plate is the axial direction of the skin plate of the sealing member attached to the inner circumference of the cutter drive body. More than the number of steps along
The shield excavator according to claim 4, wherein the shield excavator is characterized in that. The shield excavator is a mud pressure shield excavator that excavates the ground while applying a predetermined pressure to the face with the earth and sand in the cutter chamber that has become muddy.
The shield excavator according to any one of claims 1 to 5, wherein the shield excavator is characterized by the above.

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