JPH0469719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a shield-type tunnel excavator that makes a cutter assembly equipped with a plurality of cutter bits rotate eccentrically relative to a shield body, and in particular relates to a device for laying a pipe using a pipe propulsion method. This invention relates to a shield type tunnel excavator suitable for use as a shield type tunnel excavator.

(Prior art) As described in Japanese Patent Application Laid-Open No. 60-206272, one of the shield type tunnel excavators is one in which a cutter assembly including a plurality of cutter bits is rotated and rotated relative to a shield body. be.

This conventional excavator includes a crankshaft rotatably supported in a bulkhead dividing the shield body into a forward region and a rearward region thereof, the crankshaft being eccentric in the forward region and eccentric with respect to the axis of rotation. Department. A rotor is rotatably supported on the eccentric portion of the crankshaft, and a cutter assembly including a plurality of cutter bits is attached to the front end of the rotor. Each cutter bit is disposed such that its cutting edge is located on the same plane perpendicular to the axis of rotation of the cutter assembly and faces radially outward about the eccentric portion. The excavator also includes an internal gear fixed to the bulkhead and the rotor so as to forcibly rotate the rotor around the eccentric portion of the crankshaft as the crankshaft rotates. Equipped with fixed external gears.

In this excavator, when the crankshaft is rotated, the cutter assembly turns (revolutions) eccentrically by the eccentricity of the crankshaft with respect to the central axis of the shield body. Further, as the cutter assembly rotates, the engagement portion between the external gear and the internal gear sequentially moves, so that the cutter assembly rotates (rotates) around the front end of the crankshaft. Thereby, each cutter bit excavates a face when the cutter bit is moved outwardly, with its cutting edge facing outward.

However, in such excavators, the shield body tends to face upward as the excavator excavates because the cutter assembly rotates and revolves around the shield body and the cutting edge of each cutter bit faces outward. It will be changed to .

In other words, as the cutter assembly rotates, the cutter assembly receives an upward force, which causes the shield body to be receives an upward force on its front. When such a force acts on the shield body, in the case of soft ground, the shield body pushes up the earth and sand above it, and as a result, a space is formed between the front lower surface of the shield body and the ground, and this space is The earth and sand around the shield body enters, and the shield body is maintained in a slightly upward position. in this way,
Each time the shield body is excavated by the cutter bit located below with respect to the axis of rotation of the cutter assembly, the attitude of the shield body is gradually changed upward. In particular, when excavating soft ground containing rocks, a large force acts on the shield body, and as a result, the attitude of the shield body changes significantly.

On the other hand, when excavating a face with a cutter bit located above the rotational axis of the cutter assembly, the cutter assembly receives a downward force, which also applies a downward force to the shield body. However, this force only pushes the lower surface of the shield body against the earth and sand beneath it, and no space is formed between the lower surface of the shield body and the surrounding ground, so if the ground to be excavated is soft or However, the shield itself does not change its position.

(Object of the Invention) An object of the present invention is to prevent the attitude of the shield body from being changed even if either a force that makes the attitude of the shield body face upward or a force that makes the attitude of the shield body face downward act on the shield body.

(Structure of the Invention) A shield type tunnel excavator of the present invention comprises a shield main body, a partition wall that partitions the inside of the shield main body into a front region and a rear region, and a crankshaft rotatably supported by the partition wall. A cutter assembly including a crankshaft whose eccentric portion is disposed in the front region, a drive means for rotating the crankshaft, and a plurality of cutter bits, the cutter assembly being disposed in the front part of the shield body, a cutter assembly that is rotated around the rotational axis of the crankshaft as the blade rotates to excavate a face with the cutter bit; A gear mechanism comprising: a rotor supported by a rotor supporting the cutter assembly; an internal gear attached to the shield body or the bulkhead; and an external gear meshed with the internal gear and attached to the rotor. , each cutter bit having a cutting edge oriented toward the axis of rotation of the cutter assembly.

(Operations and Effects of the Invention) When the crankshaft is rotated, the rotor and the cutter assembly are eccentric to the axis of the shield body and rotate (revolution) around the rotational axis of the crankshaft. The meshing portion between the external gear attached to the rotor and the internal gear attached to the shield body or the partition wall is sequentially displaced as the rotor rotates. Therefore, the rotor and cutter assembly are also rotated (rotated) around the eccentric portion of the crankshaft.

Due to the pivoting motion (revolutionary motion) and rotational motion (rotation motion) of the cutter assembly, the cutter bit not only makes a pivoting motion and rotational motion with respect to the shield body, but also makes a so-called internal movement toward the center of the shield body. This causes a reciprocating movement in the opposite direction and in the opposite direction, that is, in the radial direction of the shield body.

In the excavator of the present invention, the internal gear is attached to the shield body or the bulkhead, and the external gear is attached to the rotor, so that while the cutter bit is rotated once around the eccentric part of the crankshaft, It is rotated multiple times around the axis of the crankshaft. That is, the Katsutabito makes multiple turning movements during one rotational movement. As a result, the cutter bit reciprocates in the radial direction multiple times during one rotational movement.

Since each Katsutabit makes multiple reciprocating movements in the radial direction of the shield body during one rotational movement, and the cutting edge of each Katsutabit faces inward, each Katsutabit is On the other hand, when moving in the direction of the axis of rotation, ie inward, the face is excavated, but when moving in the opposite direction, ie outward, it is not excavated.

For this reason, the force acting on the front part of the shield body due to the reaction force of excavation accompanying the turning and rotational movement of the cutter assembly excavates the face with the cutter bit located below with respect to the rotational axis of the cutter assembly. When excavating the face with the cutter placed above, the force is upward.

When a downward force acts on the front part of the shield body, the lower surface of the shield body is only pressed against the earth and sand beneath it, and no space is formed between the lower surface of the shield body and the surrounding ground. Even if the ground to be excavated is soft, the posture of the shield body will not change. Especially at the bottom of the face,
When the gravel that was present at the top of the face collects and is excavated, a large downward force is applied to the front of the shield body, but this force does not change the attitude of the shield body.

When an upward force acts on the front of the shield body, the face is raked down into the excavated space, so the softer the ground to be excavated, the more force will be applied to the shield body. The upward force is small, so no space is formed below the shield body and the shield body does not change its attitude. When the ground to be excavated is hard, the shield body is prevented from changing its attitude by the hard ground.

As described above, according to the excavator of the present invention, the internal gear is attached to the shield body or the bulkhead, the external gear that meshes with the internal gear is attached to the rotor, and each cutter bit is attached to the cutter assembly. Since the shield body has a cutting edge directed toward the rotation axis of the shield body, the attitude of the shield body is not changed even if either a force that makes the attitude of the shield body face upward or a force that forces it face downward acts on the shield body.

(Example) Hereinafter, an example of the shield type tunnel excavator of the present invention shown in the drawings will be described.

A shield type tunnel excavator 10 shown in FIGS. 1 to 5 includes a cylindrical shield body 12 having first and second body portions 14 and 16 that abut each other.

As shown in FIGS. 1 and 2, the first main body portion 14 includes a first cylindrical portion 14a that defines a conical crushing chamber, or a first space 18, whose inner diameter gradually decreases toward the rear. , is provided with a second cylindrical portion 14b following the rear part of the first space 18 and defining a mud room, ie, a second space 20, having a cross-sectional area larger than the cross-sectional area of the first space. The first and second cylindrical portions 14a and 14b are separably butt-connected to each other by a plurality of bolts at the rear end of the first cylindrical portion 14a and the front end of the second cylindrical portion 14b. The inner diameters of the first spaces 18 may be approximately the same.

As shown in FIG. 2, grooves extending in the circumferential direction are formed on the outer periphery of the front end and the outer periphery of the rear end of the second cylindrical portion 14b. A plurality of bolts for separably connecting the first and second cylindrical portions 14a and 14b are arranged in a flange portion formed on the outer periphery of the front end by the groove in the front end of the second cylindrical portion 14b. There is. On the other hand, a flange portion formed on the outer periphery of the rear end portion by the groove in the rear end portion of the second cylindrical portion 14b has a plurality of bolts are placed.

As shown in FIGS. 2 and 4, an inward annular lattice 22 that partitions the first and second spaces 18 and 20 is provided inside the rear end of the first cylindrical portion 14a. There is. The lattice 22 is connected to the first cylindrical portion 14a.
extends along the rear end face and also allows small excavations to move from the first space 18 to the second space 20 but large excavations to move from the first space 18 to the second space 20. to prevent you from doing
It has a plurality of openings 24 spaced at equal angular intervals around the axis of the shield body 12. The grid 22 is
It may be installed inside the front end of the second cylindrical portion 14b. The second cylindrical portion 14b is provided with a partition wall 26 that partitions the inside of the shield body 12 into a front region and a rear region.

As shown in FIGS. 2 and 4, a cylindrical sleeve 28 that extends through the partition wall 26 in the axial direction of the shield body 12 is supported on the partition wall 26 in a non-slip and non-rotatable manner. An internal gear 30 extending around the sleeve 28 is fixed to the first cylindrical portion 14a side of the partition wall 26 with a plurality of bolts. The sleeve 28 has a crankshaft 32 that passes through the sleeve 28 in the axial direction of the shield body 12.
is rotatably supported by a plurality of bearings 34. The crankshaft 32 includes a shaft portion 32a supported by the sleeve 28 and an eccentric portion or shaft portion 32b extending forward from the shaft portion. Shaft part 3
The axis of 2a is aligned with the axis of the shield body 12. On the other hand, the axis of the shaft portion 32b is
It is eccentric by a distance e from the axes of the shield body 12 and the shaft portion 32a, and the first space 1
It is located at 8.

As shown in FIG. 2, the shaft portion 32b includes a first
A rotor 36, which together with the cylindrical portion 14a constitutes a crusher, is rotatably supported by a plurality of bearings 38. The rotor 36 has a conical shape with an outer surface whose diameter gradually increases toward the rear end, and is disposed within the first space 18 . The distance between the rear end outer surface of the rotor 36 and the rear end inner surface of the first cylindrical portion 14a is smaller than the size of the opening 24 of the lattice 22 in the diametrical direction of the shield body 12. Note that a plurality of protrusions or grooves extending in the circumferential direction may be provided on the inner surface of the first cylindrical portion 14a defining the first space 18 and on the outer surface of the rotor 36.

As shown in FIGS. 2 and 3, the rotor 36
A cutter assembly 40 is fixed to the tip of the cutter. The cutter assembly 40 includes a plurality of arms 42 extending diagonally forward from the rotor 36 in the radial direction of the shield body 12, and a plurality of cutter bits 44 fixed to the arms 42. Arm 42
Each cutter bit arranged at the leading edge of the cutter has a cutting edge facing inward toward the center of rotation of the cutter assembly 40;
It has an outward cutting edge pointing in the opposite direction. On the other hand, each of the other cutter bits is arranged so that its cutting edge faces toward the center of rotation of the cutter assembly 40, that is, inward, and the cutting edge of the cutter bit whose cutting edge is disposed outside of the cutter bit. It is placed behind the cutting edge. Note that each cutter bit may be arranged such that its cutting edge is located on the same plane orthogonal to the rotational axis of the cutter assembly 40.

As shown in FIGS. 2 and 4, the rotor 36
An external gear 46 that meshes with the internal gear 30 is fixed to the rear end surface with a plurality of bolts. The external gear 46 is connected to the crankshaft 3 with respect to the internal gear 30.
The shaft portion 32b is eccentric by a distance e which is the same as the eccentricity of the shaft portion 32b with respect to the shaft portion 32a of No. 2. For this reason,
The gears 30 and 46 mesh with each other at one part in the diametrical direction, and the part where both mesh with each other is the crankshaft 3.
2 rotates around the sleeve 28, resulting in rotor 36 and cutter assembly 40.
rotates (revolutions) around the axis of the shield body 12 and rotates (rotates) around the shaft portion 32b.

As shown in FIGS. 2 and 5, the rotor 36
An annular mechanical seal 48 is disposed between the internal gear 30 and the internal gear 30 to liquid-tightly close the gap between the two. The mechanical seal 48 includes an annular groove 50 provided on the rear end surface of the rotor 36 coaxially with the rotor 36, a cylindrical cylinder 52 fitted in the groove and having a substantially uniform outer diameter, and internal teeth. gear 30
It is provided with an annular receiving seat 54 coaxially fixed to the front end surface of the internal gear, and a plurality of springs 56 that press the ring 52 toward the receiving seat 54. Groove 50
is open on the internal gear 30 side.

The ring 52 includes an annular main body that is slidably received in the groove 50 in the axial direction of the shield body 12, and a protrusion that extends rearward from the outer periphery of the rear end of the main body coaxially with the main body. The main body portion and the protruding portion of the ring 52 have the same outer diameter, and are coaxial with the rotor 36, that is, eccentrically offset from the internal gear 30 by the distance e.
The spring 56 is a compression coil spring, and the groove 5
It is placed in a hole communicating with 0.

The outer diameter dimensions of the main body portion and the protruding portion of the ring 52, particularly the rear end surface of the ring 52 and the receiving seat 5.
The diameter of the front end surface of No. 4, that is, the contact surface (sealing surface) between the ring 52 and the receiving seat 54 is at least 2e smaller than the outer diameter dimension of the receiving seat 54. That is, ring 5
The diameter of the contact surface (sealing surface) between 2 and the receiving seat 54 is:
The diameter of the outer periphery of the rear end surface (projection) of the ring 52 is
D ₁ , and the diameter of the outer periphery of the front end surface of the receiving seat 54 is
Assuming D ₂ , D ₁ ≦D ₂ −2e.

As shown in FIG.
It has an annular oil chamber 58 extending around the oil chamber 58.
contains lubricating oil. The oil chamber 58 includes a plurality of holes 60 bored in the partition wall 26, an annular groove 62 formed on the outer periphery of the sleeve 28, and the sleeve 28.
The crankshaft 3 is inserted through a plurality of holes 64 formed in the
2 and the sleeve 28. Therefore, the space between the crankshaft 32 and the sleeve 28 and the space between the partition wall 26 and the sleeve 28 are
The space between them is filled with lubricating oil.

The contact area between the front end of the rotor 36 and the tip of the crankshaft 32, the contact area between the rotor 36 and the ring 52, the contact area between the partition wall 26 and the internal gear 30, and the contact area between the sleeve 28 and the partition wall 26 are , O-rings for sealing are arranged respectively. Further, a sealing material 66 is provided between the rear end of the sleeve 28 and the rear end of the crankshaft 32 to prevent lubricating oil from flowing out.
is located. The sealing material 66 is fixed to the sleeve 28 with a plurality of bolts.

As shown in FIGS. 1 and 2, the second main body section 16 includes a first cylindrical section 16a connected to the rear end of the second cylindrical section 14b, and a second cylindrical section 16a connected to the rear end of the second cylindrical section 14b. It includes a second cylindrical part 16b inserted into the end, and a third cylindrical part 16c connected to the rear end of the second cylindrical part 16b. A support wall 68 is provided at the front end of the first cylindrical portion 16a and is perpendicular to the axis of the shield body 12, and a hole 70 for receiving the rear end of the sleeve 28 is provided in the support wall. The first cylindrical portion 16a and the second cylindrical portion 16b of the second main body portion 16 are interconnected by a plurality of jacks 72 for direction correction. Connectors 74 and 76 are arranged between the second cylindrical part 16b and the third cylindrical part 16c and between the third cylindrical part 16c and the pipe 100 to be laid.

A drive mechanism 78 for rotating the crankshaft 32 is fixed to the rear part of the support wall 68 with a plurality of bolts. The drive mechanism 78 includes an electric motor and a speed reducer, and an output shaft 80 of the drive mechanism 78 is inserted into a hole provided at the rear end of the crankshaft 32. The output shaft 80 and the crankshaft 32 are connected to the key 82.
are non-rotatably connected.

As shown in FIGS. 1 and 2, the rotor 36
A plurality of vanes 84 are attached to the conical outer surface of the rotor 36 to agitate the excavated material in the first space 18 as the rotor 36 rotates, thereby imparting fluidity to the excavated material.

The bulkhead 26 and the support wall 68 are designed to prevent muddy water from being removed from the excavator 1.
muddy water supply paths 86, 88 that supply the muddy water from the rear of the excavator 10 to the second space 20, and a muddy water discharge path (not shown) that discharges the muddy water supplied to the second space 20 together with the excavated material to the rear of the excavator 10. Equipped with. Support wall 68
A pipe 90 that guides the muddy water to the supply channel 88 is attached by a fitting 92 to the pipe 90 . A pipe (not shown) for guiding muddy water from the muddy water drainage channel to the rear of the excavator 10 is also attached to the support wall 68 by a fitting (not shown).

As shown in FIG. 2, the bottom of the second space 20 is designed to prevent the muddy water supplied from the muddy water supply channel 86 from directly reaching the muddy water drainage channel, and to prevent the muddy water from directly reaching the muddy water drainage channel. A partition 94 is provided to define a flow path for muddy water in the second space 20 so that it flows in a flow path surrounding the muddy water.

As shown in FIGS. 1, 2, and 3, a disk-shaped cap 96 is attached to the front end of the rotor 36 with a plurality of screws.
A plurality of cutters 98 are fixed to 6 for excavating the center of the face. The cutting edge of each cutter bit 98 is directed toward the center of rotation of the rotor 36.

During excavation, the drive mechanism 78 of the excavator 10 is activated and the crankshaft 32 is rotated. This results in
The rotor 36 and the cutter assembly 40 are eccentrically e relative to the axis of the shield body 12 and rotate (revolution) around the crankshaft 32 in the same direction as the rotational direction of the crankshaft 32. Since the meshing portion between the external gear 46 fixed to the rotor 36 and the internal gear 30 fixed to the partition wall 26 is sequentially displaced as the rotor 36 rotates, the rotor 3
6 and cutter assembly 40 also include shaft portion 32
b is rotated (rotated) in a direction opposite to the rotational direction of the crankshaft 32.

The pivoting and rotational movement of the rotor 36 and the cutter assembly 40 causes the cutter bits 44,98
not only makes a pivoting movement and a rotational movement together with the cutter assembly 40 with respect to the shield body 12, but also moves the shield body 12 with respect to the shield body 12.
The shield body 12 reciprocates inward toward the center of the shield body and outward in the opposite direction, that is, in the radial direction of the shield body 12.

The excavator 10 is mounted on the excavator 10 with the cutter assembly 40 being swiveled and rotated as described above.
Thrust is applied through the tube 100 by a propulsion mechanism (not shown) located behind the tube. This results in
The excavator 10 is advanced while excavating a face with the cutter assembly 40, and the pipe 100 is pushed into the excavated hole.

Since the internal gear 30 is attached to the partition wall 26 and the external gear 46 is attached to the rotor 36, the cutter bits 44, 98 are attached to the crankshaft 3.
During one rotation around the second shaft portion 32b, the crankshaft 32 is rotated multiple times around the axis of the crankshaft 32.
That is, the cutters 44 and 98 perform multiple rotational movements (revolutionary movements) during one rotational movement (rotation movement). As a result, Katsutavitsu 4
4,98 reciprocates in the radial direction multiple times during one rotational movement.

Each cutter bit 44 reciprocates multiple times in the radial direction of the shield body 12 during one rotational movement, and the cutting edge of each cutter bit is directed inward, that is, directed toward the center of rotation of the cutter assembly. Therefore, each cutter bit 44 excavates the face when the cutter bit 44 moves in the direction of the axis of rotation, ie, inwardly, relative to the shield body 12, but does not excavate when it moves in the opposite direction.

Therefore, the force acting on the front portion of the shield body 12 due to the reaction force of excavation accompanying the pivoting and rotational movement of the cutter assembly 40 is absorbed by the cutter assembly 40.
When excavating a face with a cutter placed below with respect to the axis of rotation, the force is downward; when excavating a face with a cutter placed above, the force is upward. When an upward force acts on the shield body 12, the face is raked down by the cutter bit 44 toward the excavated space, so the softer the ground to be excavated, the more the upward force acts on the shield body 12. The upward force is small, so no space is formed below the shield body 12, and the shield body 12 does not change its attitude. If the ground to be excavated is hard, the shield body 1
2 is prevented from changing its attitude by the hard ground.

When a downward force acts on the shield body 12,
The lower surface of the shield body 12 is only pressed against the earth and sand beneath it, and no space is formed between the lower surface of the shield body 12 and the surrounding ground, so even if the ground to be excavated is soft, the shield The body 12 does not change its orientation. In particular, at the bottom of the face, gravel that was present at the top of the face collects, and when excavating this, a large downward force acts on the shield body 12, but this force does not change the attitude of the shield body 12. .

The excavated earth or excavated material is received into the first space 18 . The excavated material received in the first space 18 flows from the first space 18 to the second space 20 through the openings 24 of the grid 22 while being agitated by the blades 84 as the rotor 36 rotates. do. The excavated material flowing into the second chamber 20 is mixed with the muddy water supplied into the second chamber 20, and the mixture, ie, slurry, is discharged to the rear of the excavator 10 by a discharge mechanism (not shown).

The large gravel in the excavated material that has been put into the first space 18 is moved by the rotor 36 to the shield body 1 as the rotor 36 rotates and rotates.
2 and is crushed into small pieces large enough to pass through the opening 24. The pieces crushed to a size that can pass through the opening 24 are received into the second space 20 through the opening 24. This prevents gravel from clogging the discharge pipe.

The first and second spaces 18, 20 are maintained at a predetermined pressure during excavation so that collapse of the face and heaving of the ground do not occur. However, the pressure within the second space 20 does not act on the ring 52 of the mechanical seal 48 as a force that causes the ring 52 to retreat against the force of the spring 56. That is, rotor 3
6, the ring 52 of the mechanical seal 48 is pressed toward the receiving seat 54 and rotates relative to the receiving seat 54.
The outer diameter of the ring 52 is substantially uniform;
Contact surface (sealing surface) between ring 52 and catch seat 54
Since the diameter of the ring 52 is D ₁ ≦D ₂ −2e, the rear end surface of the ring 52 is always in contact with the front end surface of the receiving seat 54 and is not exposed to the second space 20 . Therefore, the rear end surface of the ring 52 has a second
Said force due to the pressure in the space 20 does not act. Therefore, liquid tightness between the ring 52 and the receiving seat 54 is maintained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the shield type tunnel excavator of the present invention, and is a cross-sectional view of the shield main body of the excavator, FIG. 2 is an enlarged sectional view showing the excavator of FIG. 1, Figure 3 is an enlarged left side view of Figure 2;
4 is an enlarged sectional view taken along the line 4--4 in FIG. 2, and FIG. 5 is an enlarged sectional view of the mechanical seal portion. 10: Shield type tunnel excavator, 12: Shield body, 26: Bulkhead, 32: Crankshaft, 3
0: internal gear, 36: rotor, 40: cutter assembly, 44: cutter bit, 46: external gear.

Claims (1)

[Claims] 1. A shield main body, a partition wall that divides the shield main body into a front region and a rear region, and a crankshaft rotatably supported by the partition wall, the crankshaft having an eccentric portion disposed in the front region. a drive means for rotating the crankshaft; and a cutter assembly having a plurality of cutter bits, the cutter assembly being disposed at the front of the shield body, and rotating around the rotation axis of the crankshaft as the crankshaft rotates. a cutter assembly that is rotated to excavate a face with the cutter bit; a rotor that is located within the front region of the shield body and is rotatably supported on the eccentric portion of the crankshaft and supports the cutter assembly; a gear mechanism including an internal gear attached to the shield body or the partition wall, and an external gear meshed with the internal gear and attached to the rotor, and each cutter bit has a rotation axis of the cutter assembly. having a cutting edge directed towards
Shield type tunnel excavator.