JP2001323780A - Rotary excavating machine of shield propulsion machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the rotary excavating machine of a shield propulsion machine for excavating bedrock for reducing the generation of wearing based on the difference in distance from a rotation center while maintaining the durability of the bearing of an annular excavation blade. SOLUTION: Conical roller bits 9 (a, b) in a pair so that they obliquely oppose the front central part of a cutter head 2 each other are arranged at a position where the apex of a virtual cone that is circumscribed to is separated from a rotary shaft RC of the cutter head 2 by the amount of eccentricity so that they simultaneously come into contact with a surface where first to third annular blades that are integrated and have different radii orthogonally cross the rotary shaft RC, namely the rock surface of the natural ground, thus allowing the conical roller bits 9 to roll along the rock surface without sliding greatly even if the bits 9 are provided near the rotary shaft RC since the radius of a first annular blade 93 near the rotary shaft RC is small, operating an appropriate amount of prying force to the rock surface of the natural ground and hence preventing the compaction phenomenon of grit from occurring easily, and greatly reducing the wearing of the tool nose of the roller bits that are generated by the extreme difference in slide friction caused by the difference in arrangement positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of annular excavating blades having a wedge-shaped cross-section at the center thereof, and is configured to crush and crush a rock inserted therein when revolving while contacting the rock. The rotary excavator of the shield machine.

[0002]

2. Description of the Related Art A shield excavator that excavates in the ground to form a tunnel behind it has approximately two types of cutter heads (the tip of the shield excavator is rotatable depending on the geology of the ground to be excavated). And a rotary excavator that excavates the abutting ground). That is, when excavating soft ground such as soil or sand, a cutter head in which a large number of excavating blades called cutter bits are planted on the front surface,
Also, when excavating hard ground such as bedrock, for example,
As disclosed in JP-A-7-82988,
A center cutter provided with a disc-shaped excavating blade called a plurality of roller bits having the same diameter and arranged coaxially and rotatably at the center of the front surface is used. In the cutter head used for rock excavation, when the roller bit revolves and rotates while contacting the ground, it receives thrust and presses into the ground to crush the ground, and the change in the rotation direction of the roller bit The ground is crushed by the twisting action.

However, in rock excavation by a cutter head using such a roller bit, a compaction phenomenon occurs in which excavated sand and gravel clog the gaps between the roller bits, so that some roller bits cannot be rotated. In some cases, the outer ring portion of the roller bit partially wears violently, causing uneven wear. In addition, if the mounting position of the roller bit is close to the outer peripheral part, the change in the rotation direction at the time of revolution is gradual, so that smooth rotation is possible, but if the mounting position is close to the center of rotation, the change in the rotation direction during the revolution As the roller bit becomes sharp, it becomes difficult to rotate smoothly, so that it is easily worn due to a large frictional force.

[0004] In view of the above, the outer diameter of the roller bit is changed in accordance with the mounting position by taking a hint on the shape of the drilling blade conventionally used in the oil drilling apparatus. It was considered to reduce the outer diameter of the bit. For example, Japanese Patent Application Laid-Open No. 8-170492 discloses that a plurality of disc cutters (roller bits) are arranged in a plurality of rows on a frame (cutter head) rotatably provided at the tip end, and the diameter of each disc cutter is set. An invention of a rotary excavator set so as to be proportional to a radius of a position from a rotation center is disclosed.

[0005]

According to the above-mentioned prior art, since each disk cutter rotates at the same rotational speed when revolving while abutting on the ground, it can rotate without slipping. Since the diameter of the disk cutter near the center of rotation is small, the disk cutter can easily follow the change in the rotation direction, and can reduce the frictional force caused by the radial sliding at the time of revolution. Since this rotary drilling device is used for a small-diameter propulsion device that excavates the ground made of soil mixed with gravel, the reaction force from the ground acting on the disk cutter is not so large, A large rotational driving force is not required for the frame, and therefore, the durability of the bearing can be maintained even if the disk cutter has a small diameter. However, when used in a medium to large diameter propulsion device for excavating hard rock, the reaction force from the ground acting on the disk cutter becomes strong, and moreover,
Since the reaction force acts obliquely with respect to the rotation axis, the durability of the bearing of the disk cutter having a small diameter cannot be maintained.

In addition, if only hard rock is pressed into the rock by the wedge action of the roller bit to excavate the hard rock, the rock cannot be efficiently crushed, and the rock slides in the radial direction at the time of revolution. Since it is essential to use the rocks, the above-mentioned prior art in which almost no slippage occurs is not necessarily suitable for excavating hard rock. The present invention has been made to solve such a problem in the related art, and rock excavation capable of reducing occurrence of uneven wear based on a difference in distance from a rotation center while maintaining durability of a bearing of an annular cutting blade. It is an object of the present invention to provide a rotary excavator of a shield excavator for a vehicle.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a plurality of annular excavating blades having a wedge-shaped cross section and crushing and crushing a rock are integrally formed in a virtual cone. Apexes of each virtual cone in which a plurality of annular cutting blades of a conical composite excavation body which are arranged in a pair and are opposed to each other are inwardly projected. Are set at positions shifted from the rotation center of the rotary excavator, and the trajectories drawn when each of the plurality of annular excavation blades abut on the ground and revolve have different diameters, more preferably, each virtual The vertices of the cones are opposite to each other with respect to the center of rotation of the rotary excavator, the amount of deviation from the center of rotation of the rotary excavator is set equal, and the apex angle of each virtual cone inscribed by the annular drilling blade Equal or multiple rings Maximum diameter of Kezuha is those to be set substantially equal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view passing through the center of rotation of the tip of a shield machine according to an embodiment of the present invention, FIG. 2 is a partially enlarged view showing a center cutter portion, and FIG. 3 is a side view of a conical roller bit. 4 is a front view of the shield machine, FIG. 5 is a longitudinal sectional view showing the first half of the shield machine, and FIG. 6 is a sectional view of a conical roller bit. In these figures, 1 is the ground where the shield machine excavates,
2 is rotatably attached to the tip of a shield machine described later, and receives a propulsive force from the shield machine and a rotational driving force from a rotary drive device described later to excavate the ground 1 at a shallow depth. A substantially cylindrical cutter head 3 is formed between the inner space of the cutter head 2 and a partition wall described below, and a gravel storage chamber for taking in and storing sand and gravel formed by excavation. A partition 5 for partitioning between the side and a machine room described below is a machine room for accommodating each drive mechanism of the shield machine body.

Reference numeral 6 designates a helical member which rotates in contact with the inside of a transfer cylinder opened in the lower front part of the partition wall 4 to take in the gravel stored in the gravure storage chamber 3 and transport it to the rear half of the shield machine. Rotating conveying device, 7 is the cutter head 2
A rotating shaft integrally attached to the center of the inner bottom of the shaft and rotatably supported by a bearing fixed to the center of the partition wall 4;
Reference numeral 8 denotes a rotary drive device attached to the partition wall 4 and applying a rotary drive force to the cutter head 2 via a gear mechanism.
b) a pair of conical roller bits rotatably attached to the center of the front surface of the cutter head 2 so as to be obliquely opposed to each other; Roller bit consisting of a disk-shaped roller bit independently and rotatably mounted, 21 is a shield machine body, 91 is a cone cutter inscribed in a virtual cone CN, and 92 is a conical roller bit 9 ( a, a support arm for supporting the bearings of 9)
Reference numerals 3, 94, and 95 denote wedge-shaped cross sections that are fitted into the abutment ground and crush the bedrock, and are formed in an annularly protruding shape.
An annular blade, 96 is a bearing for the conical roller bit 9 (a, b), 97 is a cemented carbide buried in the cutting edge of the first to third annular blades 93, 94, 95, and 98 is a conical cutter 91. It is a bearing that supports freely.

[0010] As shown in FIG. 4, the continuous roller bit 10 includes two pairs of two columns each of two columns of three columns extending in the radial direction which form a structure on the front surface of the cutter head 2. A pair of the columns are rotatable around a rotation axis in the radial direction, and a pair of the columns is a pair of the columns, and three pairs of the annular members constituting the outer periphery of the front surface of the cutter head 2. The pair is rotatably provided around a rotation axis inclined backward with respect to the radial direction. As shown in FIG. 2 or FIG. 3, the pair of conical roller bits 9a and 9b each have a circumscribed virtual cone CN in contact with a plane orthogonal to the rotation axis RC of the cutter head 2, and their vertices Oa, Ob is located at a position away from the rotation axis RC by the amount of eccentricity BDa, BDb in the same direction. And the conical roller bits 9a, 9
The rotation axis JC of b intersects with the plane perpendicular to the rotation axis RC at the same journal angle θ.

Next, the operation of this embodiment will be described. The shield excavator body 21 is pushed forward by a plurality of shield jacks (not shown) and moves forward, while the rotation driving device 8 is driven, and the cutter head 2 is rotated by the driving force transmitted via the gear mechanism. As a result, the conical roller bits 9a and 9b and the continuous roller bit 10 provided on the front surface of the cutter head 2 abut on the rock of the ground and revolve while rotating, and crush and crush the inserted rock. When the continuous roller bit 10 comes into contact with the ground, each rotation axis is parallel to the rock surface of the ground. When the roller bits 9a and 9b come into contact with the ground, each rotation axis JC forms a journal angle θ with respect to a plane orthogonal to the rotation axis RC, that is, the rock surface of the ground. When this acts, the bearing may be broken.

Therefore, in this embodiment, the first to third annular blades 93, 94, 95 of the conical roller bit 9 (a, b) are formed so as to form a part of an integrally formed conical cutter 91, The bearing 96 is also designed to have a strength to withstand a reaction force obliquely acting on the rotation axis JC received from the ground. Then, the first to third annular blades 93,
The shapes of the cutting edges 94 and 95 are also asymmetrical with respect to the plane including the cutting edges. The surface on the vertex O side is almost flat, and the surface on the opposite side forms a conical shape opposite to the virtual cone CN. It has a shape like the upper part. With such a shape, when the cutting edges of the first to third annular blades 93, 94, and 95 come into contact with the rock surface of the ground, they are fitted in a substantially symmetric wedge shape. The gravel of the bedrock pressed or crushed by the conical cutter 91 and the continuous roller bit 10 falls into the gravel storage chamber 3 and is taken into the revolving transfer device 6 having a transfer cylinder opened at the lower part thereof, and shielded. It is transported to the rear part of the excavator body 21.

As described above, the first to third annular blades 93, 9
4, 95 are formed integrally with the conical cutter 91 and the vertex O is not on the rotation axis RC of the cutter head 2;
When the conical cutter 91 revolves while abutting against the rock surface of the ground, the first to third annular blades 93, 94, and 95 roll while fitting into the rock surface and at least two of them. Slides in the circumferential direction and the radial direction, that is, performs a twisting operation, so that the cracks on the rock surface of the ground caused by the insertion of the first to third annular blades 93, 94, 95 are enlarged, and the crushing and crushing are facilitated. .

As described above, in the present embodiment, a pair of conical roller bits 9 (a, b) are formed at the center of the front surface of the cutter head 2 so as to be obliquely opposed to each other. Are formed at positions separated from the rotation axis RC of the cutter head 2 by the amount of eccentricity BD (a, b), and the first to third annular blades 93, 94, 95 formed integrally and having different radii are orthogonal to the rotation axis RC. In other words, since the conical roller bit 9 is provided at a position close to the rotation axis RC, the first annular blade 93 close to the rotation axis RC is particularly provided even if the conical roller bit 9 is provided at a position close to the rotation axis RC. The radius of the rock is small, so it can roll along the rock surface without slipping and apply a moderate amount of prying force to the rock surface of the ground. Arising from extreme differences in sliding friction It is possible to considerably reduce the uneven wear of the cutting edge of the Rabitto.

In this embodiment, a pair of conical roller bits 9a and 9b are formed of the same conical cutter 91, and the vertex O of the virtual cone CN has the same journal angle θ and the rotation axis RC of the cutter head 2 has the same angle. Are arranged on the same side so as to oppose to positions separated by eccentricities BDa and BDb, but the vertex O of the virtual cone CN circumscribing the conical roller bit 9 is on the opposite side to the rotation axis RC, And,
If it is arranged at a position where the amount of eccentricity BD is almost equal,
Uneven wear due to a difference in the arrangement position of the conical roller bit 9 can be further reduced.

FIGS. 7 and 8 are partially enlarged views showing a center cutter portion according to a modification of the present embodiment. In these figures, 9c, 9d and 9e, 9f are pairs of conical roller bits according to the first and second modifications, respectively. Both conical roller bits 9c, 9d circumscribe the same virtual cone CN. That is, the apex angles of the curved surfaces at the vertices Oc and Od are mutually different, and the conical roller bits 9e and 9f are formed at the vertices Oe and Of.
Virtual cones CN having different apex angles formed by curved surfaces at
So that the diameters of the third annular blades 95 are substantially equal to each other, and the vertex O of the virtual cone CN is located on the opposite side to the rotation axis RC, and the eccentric amounts BDc, BD
The diameters of the first to third annular blades 93, 94, 95 are respectively set such that d and the eccentric amounts BDe, BDf are equal to each other.

As described above, the apex O of the virtual cone CN is located on the opposite side to the rotation axis RC, and the eccentricity BD is made equal. Uneven wear can be almost eliminated. When the first and second modifications are adopted, there is an advantage that the radial arrangement of the rotation axis RC and the arrangement in the rotation axis RC direction with a margin can be provided.

[0018]

As described above, according to the first aspect of the present invention, the plurality of annular excavating blades are integrally formed so as to project into the conical composite excavating body inscribed in the virtual cone. As a result, the annular drilling blade can revolve smoothly even when it is located near the center of rotation of the rotary drilling machine, while preventing the occurrence of consolidation due to excavated sand and gravel. Generation can be prevented, and the durability can be maintained even when a large reaction force is received from the ground. According to the second aspect of the present invention, the position of the apex of each virtual cone in which the plurality of annular cutting blades of the conical composite excavating body arranged in a pair are inscribed is shifted from the rotation center of the rotary excavator. And the trajectories drawn by each of the plurality of annular excavation blades have different diameters, so that efficient rock excavation can be performed even when only a small number of conical composite excavations are provided. Can be.

According to the third aspect of the present invention, the vertices of the virtual cones are located on opposite sides of the rotation center of the rotary excavator, and the amount of deviation from the rotation center of the rotary excavator is set equal. As a result, uneven wear due to the mounting position of the annular excavation blade can be almost eliminated. According to the invention as set forth in claim 4, since the apex angles of the respective virtual cones inscribed by the annular excavation blade are made equal, the rotary excavator of the conical composite excavation body which is arranged in a pair and opposed to each other is formed. The mounting width in the radial direction can be set small. According to the fifth aspect of the present invention, since the maximum diameters of the plurality of annular excavating blades are set to be substantially equal, an axial direction of the rotary excavator of the conical composite excavating body which is arranged in a pair and opposed to each other is formed. The mounting width can be set small.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a shield machine according to an embodiment of the present invention, which passes through the center of rotation of a tip end portion.

FIG. 2 is also a partially enlarged view showing the center cutter part.

FIG. 3 is a side view of a conical roller bit.

FIG. 4 is a front view of the shield machine.

FIG. 5 is a longitudinal sectional view showing the first half of the shield machine.

FIG. 6 is a sectional view of a conical roller bit.

FIG. 7 is a partially enlarged view showing a center cutter unit according to a modification of the embodiment.

FIG. 8 is a partially enlarged view showing a center cutter portion according to another modification of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground 2 Cutter head 3 Gravel storage room 4 Partition wall 7 Rotating shaft 8 Rotation drive device 9a-9f Conical roller bit 10 Continuous roller bit 21 Shield excavator main body 91 Conical cutter 93 1st annular blade 94 2nd annular blade 95 Third annular blade 96 bearing 97 cemented carbide 98 bearing

Claims (5)

[Claims] 1. A plurality of annular excavating blades having a wedge-shaped cross section and rotatably attached to the tip of a shield excavator for excavating underground to crush and crush rocks that have revolved and fitted while abutting. In the rotary excavator of the cylindrical shield machine having a central portion, the plurality of annular excavating blades are integrally formed so as to protrude into a conical composite excavating body inscribed in a virtual cone. A rotary excavator for a shield machine. 2. A vertex of each virtual cone in which a plurality of annular cutting blades of a conical composite excavating body arranged in a pair and opposed to each other is set at a position deviated from a rotation center of a rotary excavator. 2. The rotary excavator for a shield machine according to claim 1, wherein the trajectories drawn when the plurality of annular digging blades make contact with the ground and revolve have different diameters. 3. A vertex of each virtual cone in which a plurality of annular cutting blades of a conical composite excavating body arranged in a pair are inwardly opposed to each other with respect to the rotation center of the rotary excavator. 3. The rotary excavator for a shield machine according to claim 2, wherein the amount of deviation from the rotation center of the rotary excavator is set to be equal. 4. An apex angle of each virtual cone which is inscribed by a plurality of annular cutting blades of a conical composite excavating body arranged in a pair and facing each other is set to be equal. Drilling machine for shield machine. 5. The rotation of a shield machine according to claim 3, wherein the maximum diameters of the plurality of annular cutting blades of the conical composite excavating body arranged in pairs are substantially equal. Excavator.