JPH045120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a shield type tunnel excavator, and more particularly to a shield type tunnel excavator suitable for use in a pipe propulsion method.

(Prior Art) In the pipe propulsion method, a shield type tunnel excavator is placed at the forefront of a plurality of pipes being propelled. While the face is excavated by the operation of the rotary cutter head installed on this tunnel excavation machine, a propulsion jack installed in the shaft and adjacent to the rearmost pipe applies thrust to the said pipe and the tunnel excavation machine in front of it. and thus both are propelled into the excavated ground by the action of the cutter head.

The rotary cutter head is disposed in front of and spaced from the bulkhead across the interior of the shield body, and during propulsion of the tunnel boring machine and the pipe, excavated material at the face passes through the cutter head and into the cutter head. and said bulkhead and fills the bulkhead front area. The excavated material filling the area in front of the bulkhead has the function of transmitting the earth pressure of the face to the bulkhead of the shield body and the reaction force of the bulkhead to the face, and due to the balance between this reaction force and the earth pressure, the face does not collapse or bulge. is maintained stably.

(Problems to be Solved by the Invention) Conventionally, the excavated material is rotated together with the cutting head in the area in front of the bulkhead, and is directed to a soil discharge means such as a screw conveyor provided at the lower part of the bulkhead, and the excavated material is Although the excavated material was discharged behind the partition wall through a means, a large frictional force was exerted between the rotating excavated object and the partition wall, and a large torque was required to rotate the cutting head. This has hindered the miniaturization of the drive device for the cutter head, and has made it difficult to miniaturize the shield type tunnel excavator for the propulsion method, that is, to reduce the diameter of the shield body.

Reduction of the frictional force between the excavated material and the bulkhead must be taken into consideration, especially when excavating and propulsion in sandy and gravelly ground.For this purpose, the effective friction reduction methods that have been implemented in the past include the use of high concentration at the face. There are examples of applying pressurized mud to stabilize the mud and give fluidity to the excavated material. However, use of this pressurized mud water requires subsequent treatment of the muddy water mixed with excavated materials, and this treatment has problems such as equipment and costs. In addition, since the frictional force increases in proportion to the pressure exerted on the excavated material filling the area in front of the bulkhead, it is necessary to reduce this pressure as low as possible in order to reduce the frictional force. However, in order to stabilize the face, the pressure acting on the excavated material cannot be lower than the main earth pressure of the ground at the face, so there is a natural limit to reducing the frictional force through the lubricating action of mud. .

SUMMARY OF THE INVENTION An object of the present invention is to reduce the frictional force acting between the bulkhead and the cutter head, which is caused by rotating the cutter together with the cutter head in the area in front of the bulkhead between the bulkhead and the cutter head. .

Another object of the present invention is to provide a shield type tunnel excavator that can be used in a wide range of ground ranging from soft ground to hard ground.

(Means for Solving the Problems) A shield type tunnel excavator according to the present invention includes a shield body having a front portion whose inner diameter gradually decreases toward the rear, and a shield body that crosses the shield body at the rear of the front portion. a crankshaft rotatably supported on the bulkhead, the crankshaft having one end connected to a drive mechanism provided at the rear of the bulkhead and the other end extending in front of the bulkhead; a conical, truncated conical, or cylindrical rotary head rotatably supported on the other end of the crankshaft and disposed within the front portion of the shield body; and a gear mechanism for forcibly rotating the rotary head. a gear mechanism including an internal gear fixed to the partition wall, an external gear fixed to the rotary head and meshing with the internal gear, and discharging the excavated material from the front area of the partition wall to the rear area thereof; and means to do so.

Further, the shield type tunnel excavator according to the present invention includes a shield body having a front portion having a substantially constant inner diameter, a partition wall provided across the shield main body behind the front portion, and a partition wall that rotates. a crankshaft rotatably supported, the crankshaft having one end connected to a drive mechanism disposed behind the bulkhead and another end extending forward of the bulkhead; and a crankshaft rotatable at the other end of the crankshaft; a conical or frusto-conical rotary head supported by and disposed within the front portion of the shield body;
A gear mechanism for forcibly rotating the rotary head, the gear mechanism including an internal gear fixed to the partition wall and an external gear fixed to the rotary head and meshing with the internal gear; and means for discharging the excavated material to an area behind the excavated material.

According to the present invention, the rotary head that rotates and rotates in a direction opposite to the direction of the rotation and the inner circumferential surface of the front portion of the shield body consolidate the excavated material received between them and straighten the excavated material. Since the excavated material is moved and guided to the discharge port, it is possible to reduce the friction that acts between the excavated material and the partition wall and other parts of the shield body.

(Example) Examples of the present invention will be described below with reference to the drawings.

Shield type tunnel excavator 10 according to the present invention
As shown in FIG. 1, the shield body 12 has a front portion 12a, a middle portion 12b and a rear portion 12c, and a generally conical rotary head 16 disposed in a space 14 within the front portion 12a of the shield body. including. When the tunnel excavator 10 is used in a pipe propulsion method, as is well known to those skilled in the art,
A plurality of steel or concrete pipes (not shown) are connected behind the shield body 12, and a hydraulic jack (not shown) placed in the shaft that applies thrust to these pipes is connected behind the shield body 12.

The front portion 12a of the shield body 12 has an inner diameter that gradually decreases toward the rear, and the inner peripheral surface 1
8 surrounds the space 14. A partition wall 20 is provided at a rear intermediate portion 12b of the front portion 12a of the shield body 12, and extends across the shield body. Shield body 12
Also located behind the bulkhead 20 in its intermediate portion 12b are a plurality of direction correction jacks 22 (only one of which is shown in FIG. 1).

A crankshaft 24 is provided for supporting the rotary head 16 and causing eccentric movement thereof. Shaft portion 2 on one end side of this crankshaft 24
5a is supported by a pair of rolling bearings 28 attached to a collar 26 attached to the partition wall 20. Further, the shaft portion 25a is connected to an output shaft 31 of a drive mechanism 30 including an electric motor and a speed reducer, which are fixed to the partition wall 20 with bolts 29b via a bracket 29a.
The key is locked. On the other hand, the shaft portion 25b at the other end of the crankshaft 24 supports the rotary head 16 via a pair of rolling bearings 32 mounted on the rotary head 16. crankshaft 24
has an eccentricity e (see FIGS. 1 and 2) between its shaft portion 25a and shaft portion 25b.

A pair of tubes 3 are provided in the lower part of the partition wall 20 and pass through the partition wall.
4,36 are attached. these tubes 3
4 and 36 are both opened toward the front of the partition wall, and are connected to the partition wall 20 in the intermediate portion 12b of the shield main body.
It communicates with a shear chamber 38 formed in the front. The pipe 34 is a liquid supply pipe for supplying liquid such as fresh water or muddy water to the front of the partition wall 20, and the pipe 36 is for supplying surplus water in the ground or excavated materials such as earth and sand together with the liquid supplied to the front of the partition wall. This is a discharge pipe for discharging water. Instead of this example of liquid transport, the excavated material can be discharged by
It is also possible to use a known screw conveyor.

An internal gear 40 is attached to the partition wall 20, and an external gear 42 that meshes with the internal gear 40 is attached to the rotary head 16. In the illustrated example, the internal gear 4
0 is provided on the inner peripheral surface of a cylindrical member 44 having a flange 43. This cylindrical member 44 is fixed to the partition wall 20 by bolts 46 passing through the flange 43. On the other hand, the external gear 42 has a flange 47
It is provided on the outer circumferential surface of the cylindrical member 48 having a diameter. This cylindrical member 48 is fixed to the rotary head 16 by bolts 50 passing through the flange 47. The crankshaft 24, internal gear 40, and external gear 42 rotated by the drive mechanism 30 constitute a planetary gear mechanism. When the crankshaft 24 is rotated, the rotary head 16 makes an eccentric rotational movement, and at the same time is forcibly rotated by the meshing of the internal gear 40 and the external gear 42. The rotating direction of the rotary head 16 at this time is opposite to the rotating direction of the crankshaft 24. The eccentric rotation movement of the rotary head 16 is caused by the shaft portion 25a of the crankshaft 24.
The rotation of the rotary head 16 is rotation about its own axis.

The rotary head 16 includes a cutter assembly 60 secured to its distal end, as shown in FIGS. 1 and 3. Cutter assembly 60, in the illustrated example, includes a plurality of spokes 62 radially disposed from rotary head 16 and a plurality of bits or tips 64 on each spoke.
As an alternative to the above-described example, a cutter assembly (not shown), known per se, can also be provided, comprising a disc with at least one slit and a plurality of bits or tips projecting forward from said slit.
The cutter assembly 60 is not required when the tunnel excavator 10 is used in soft ground and can be removed in advance.

In order to improve the ability of the rotary head 16 to crush excavated materials, especially gravel, the front portion 1 of the shield body
A plurality of protrusions 66, 68 each having a pointed end are provided on the inner circumferential surface 18 of the rotary head 2a and the outer circumferential surface 17 of the rotary head 16. These protrusions 6
6 and 68 are the inner circumferential surface 18 and the outer circumferential surface 1
It can be provided continuously or intermittently in the circumferential direction of 7, or it can be provided continuously or intermittently in a spiral shape.

The tunnel excavator 10 includes a rotary head 16.
A sealing device 7 for sealing between the partition wall 20 and the partition wall 20
0 is set. The sealing device 70 is a ring 7
2 and a coil spring 74. The ring 72 has an inner circumferential groove 75 open to the rear of the rotary head 16.
The ring 72 is disposed on the outer periphery of the cylindrical member 48 inside, and the ring 72 is movable in the axial direction of the crankshaft 24. An O-ring 76 is arranged around the outer periphery of the ring 72. The coil spring 74 is
The ring 72 is disposed in a hole 77 that communicates with the inner circumferential groove 75, and presses the ring 72 toward the end surface of the cylindrical member 44 to achieve a sealing effect between the two. According to the sealing device 70, even if the ring 72 and the cylindrical member 44 are worn in their contact area, the spring 7
Since the ring 72 is always pressed against the cylindrical member 44 by the ring 72, the desired sealing effect can be permanently maintained between the two. Instead of the illustrated example,
arranging the ring of the sealing device on the partition wall 20 side;
A sealing effect may be achieved between the ring and the cylindrical member 48. In either example, lubricating oil stored in an oil bath 80 is provided between the ring 72 and the cylindrical member 44 through the passages 82 and 8.
4, 86, 88, bearing 28, and passage 90.

In the illustrated example, the shield main body 12 has a front portion 12a whose inner diameter gradually decreases toward the rear,
The rotary head 16 disposed in the front section is generally conical, but instead of a conical rotary head, a truncated conical or cylindrical rotary head may be used. Further, when the rotary head is shaped like a cone or a truncated cone, the inner diameter of the shield body can be made substantially constant.

To explain the operation of the tunnel excavator 10, when the crankshaft 24 is rotated by the drive mechanism 30,
The rotary head 16 is pivoted eccentrically by e from the center of the shield body 12. This turning direction is the same as the rotation direction of the crankshaft 24. As the rotary head 16 rotates, the meshing portion of the external gear 42 fixed to the rotary head 16 and the internal gear 40 fixed to the partition wall 20 sequentially moves, so that the rotary head 16 is centered around the shaft portion 25b of the crankshaft 24. As a result, the crankshaft 24 rotates in the opposite direction. In this state,
When thrust is applied from the rear of the concrete pipe by a propulsion jack (not shown), the tunnel excavator 10 moves forward, excavates with the face, and excavates the shield body 1.
Excavations, such as earth and sand, received within the shield 2 are consolidated between the rotary head 16 and the shield body 12 and are sent rearward. In this way, the excavated material that has reached the shear chamber 38 is discharged to the rear of the partition wall 20 via the pipe 36.

According to the present invention, the rotary head that rotates and rotates in a direction opposite to the direction of the rotation and the inner circumferential surface of the front portion of the shield body consolidate the excavated material received between them and straighten the excavated material. Since the excavated material is moved and guided to the discharge port, it is possible to reduce the friction that acts between the excavated material and the partition wall and other parts of the shield body. Therefore, a relatively small drive device can be used to rotate the rotary head and cutter assembly, and when the present invention is applied to a shield type tunnel excavator for the pipe propulsion method, its miniaturization, i.e. It becomes possible to reduce the diameter of the shield body.

In addition, when the rotary head rotates in the opposite direction to the rotation direction of the crankshaft, the rotary head acts to pull the excavated material between the rotary head and the shield body. The effect of consolidating objects can be further enhanced.

[Brief explanation of drawings]

1 is a longitudinal sectional view of a shield type tunnel excavator according to the present invention, FIG. 2 is a reduced sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a longitudinal sectional view taken along line 2-2 in FIG. -3
It is a reduced end view seen from the direction. 10: Shield propulsion device, 12: Shield body, 12a: Front part of shield body, 16: Rotary head, 20: Bulkhead, 24: Crankshaft, 3
0: Drive mechanism, 38: Shear chamber, 40: Internal gear, 4
2: external gear, 60: cutter assembly, 70: seal device.

Claims (1)

[Scope of Claims] 1. A shield body having a front portion whose inner diameter gradually decreases toward the rear, a partition wall provided across the shield main body behind the front portion, and rotatably supported on the partition wall. a crankshaft having one end connected to a drive mechanism provided at the rear of the bulkhead and the other end extending in front of the bulkhead; and a crankshaft rotatably supported by the other end of the crankshaft. and a conical, truncated conical, or cylindrical rotary head disposed in the front portion of the shield body, a gear mechanism for forcibly rotating the rotary head, and an internal gear fixed to the partition wall, and the rotary head. A shield type tunnel excavator comprising: a gear mechanism fixed to a head and including an external gear meshing with the internal gear; and means for discharging excavated material from an area in front of the partition wall to an area behind the partition wall. 2. The crankshaft further includes a sealing device for sealing a space between the partition wall and the rotary head, the sealing device being provided on one of the partition wall and the rotary head and movable in the axial direction of the crankshaft. 2. A shield tunnel excavator as claimed in claim 1, comprising a ring and a spring biasing the ring toward the other of the bulkhead and the rotary head. 3. The shield type tunnel excavator according to claim 1, wherein the rotary head is provided with a plurality of protrusions having sharp edges on its circumferential surface. 4. The shield type tunnel excavator according to claim 1, wherein the shield main body is provided with a plurality of protrusions having pointed ends on the inner circumferential surface of the front portion thereof. 5. Claim 1 further includes a cutter assembly provided at the front end of the rotary head.
The shield type tunnel excavator described in . 6. A shield main body having a front portion having a substantially constant inner diameter, a partition provided across the shield main body behind the front portion, and a crankshaft rotatably supported by the partition, the partition wall a crankshaft having one end connected to a drive mechanism provided at the rear of the partition wall and the other end extending in front of the partition; a crankshaft rotatably supported on the other end of the crankshaft and within the front portion of the shield body; a conical or truncated conical rotary head arranged;
A gear mechanism for forcibly rotating the rotary head, which includes an internal gear fixed to the partition wall and an external gear fixed to the rotary head and meshing with the internal gear, and a gear mechanism from the front area of the partition wall. and means for discharging excavated material to an area behind the shield type tunnel excavator.