JPH0735915Y2 - Shield excavator - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator suitable for constructing a double-track subway road or the like underground.

[0002]

2. Description of the Related Art A shield excavation method for excavating and forming a horizontal shaft having a unique sectional shape suitable for constructing an underground structure such as a double-track subway by one excavation work using one shield machine. , And the shield excavator used in this method has already been proposed by the present applicant as JP-A-57-197395.

This shield excavator has two rotary cutters, and when excavating with these rotary cutters,
It is configured so that an eyebrow-shaped or dharma-shaped excavated cross-sectional shape obtained by superimposing a part of a plurality of circles can be obtained.

[0004]

However, as shown in FIG. 8, the rotary cutter of this shield excavator has a substantially cross-shaped spoke 8a, 8b structure in which a large number of bits 9 are provided on the front surface, respectively. However, since it is not possible to place a large number of bits 9 in the outermost periphery where the excavation is the most severe, the durability of the rotary cutter is poor, and during long-distance excavation or in the gravel layer excavation, the bit 9 is severely damaged, There is a problem in that the replacement is so frequent that the workability is poor and that it takes time and money.

The present invention has been proposed in view of the above points, and an object of the present invention is to make the shape of a rotary cutter substantially fan-shaped so as to widen toward the outermost peripheral portion or a shape similar thereto so that the outermost peripheral portion is formed. Another object of the present invention is to provide a shield excavator suitable for long-distance excavation, in which a large number of bits are provided to improve the durability of the rotary cutter against excavation at the outermost periphery.

[0006]

[Means for Solving Problems] That is, the present invention is
In a shield excavator for obtaining an excavation cross section in which a plurality of circles are adjacent to each other and a part of which is overlapped, a plurality of rotary cutters 3 and 3 ′ for excavating each circle cross section are arranged on substantially the same plane, and Each of the cutter bodies of the rotary cutters 3 and 3'is formed into a substantially fan shape or a shape similar to that in which the outermost peripheral shape is widened with respect to the center part thereof, and the respective cutter bodies mesh with each other in the rotation direction of the cutter body. Are arranged with various phase differences, and a large number of bits 9 for face excavation are also provided on the outermost periphery of each cutter body.
9'is provided to achieve the above object.

[0007]

In the present invention, the cutter body, which is provided with a large number of bits at the outermost peripheral portion of the cutter body under the most severe conditions during excavation, is not substantially fan-shaped from the conventional one having a cross shape. A shape similar to that is used to improve the strength and durability of the cutter body.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention. In FIG. 1, reference numeral 1 indicates two circles having the same diameter. The distance between the centers of the two circles is larger than the radius of the circle but smaller than the diameter. When arranged side by side in this way, the shield outer cylinder is made of, for example, a steel plate and has a so-called circular shape or dulma shape formed by the outer peripheral edges of the two circles.

Reference numeral 2 is a face mud chamber formed on the front end side of the shield outer cylinder 1, and 3 and 3'are centered around the two circles forming the cross-sectional outer shape of the outer cylinder 1 as a center of rotation. This is a rotary cutter of the base. The rotary cutters 3 and 3'are provided with center bits 4 and 4'on the tips respectively, and center shafts 6 and 6'where the mud earth material injection pipes 5 and 5'are formed on the center line. And the spokes mounted on the front ends of the center shafts 6 and 6'via bearings 7 and 7 '.
8a, 8b, 8a ', 8b' substantially C-shaped cutter spokes 8, 8 ', and a plurality of face excavating bits 9, 9'mounted on the front surface of each cutter spoke 8, 8', A plurality of mixing blades 10, 10 'mounted on the rear surface of the cutter spokes 8, 8'and the outermost peripheral portions of the spokes 8a, 8b, 8a', 8b 'constituting the cutter spokes 8, 8'are connected. Then
Also, arc-shaped members 11 and 11 'having a large number of face-digging bits 9 and 9', respectively, on the front surface, and similar drilling members 12 provided at the central portions of the spokes 8a and 8b and arc-shaped members 11 and the like,
12 ', the cutter body consisting of the cutter spokes 8 and 8', the arcuate members 11 and 11 ', etc., is gradually tapered toward the outermost periphery when the bearings 7 and 7'are viewed from the front. It is characterized in that it is formed in a substantially fan shape that spreads out.

A partition wall 13 is provided in front of the shield cylinder 1, and the partition wall 13 and the inner peripheral wall 1a in front of the shield cylinder are provided.
The face mud chamber 2 is sectioned and formed by and. The partition wall 13 is provided with an outer peripheral partition wall 14 which is erected from the inner peripheral wall 1a of the shield cylinder 1 toward the inner side, and rotary cutters 3, 3'which are located inside the outer peripheral partition wall 14 and are substantially flush with each other. And a substantially circular rotary partition wall 15 and 15 ′ that support and drive the respective.

Next, the support and rotation mechanism of the rotary cutter 3 will be described. The center shaft 6 penetrates through the central portion of the rotary partition wall 15, and its rear end is rotatably supported by a seal / bearing 17 provided on a support plate 16 located behind the rotary partition wall 15. Further, a cutter support beam 18 is provided between the rear central portions of the spokes 8a and 8b and the front portion of the rotary partition wall 15, whereby the rotary cutter 3 rotates integrally with the rotary partition wall 15.

That is, a cutter driving motor 19 is attached to the support plate 16, and a pinion 20 provided on the motor shaft is meshed with a large gear 21 connected to the rear portion of the rotary partition wall 15. The rotating portion 21a of the large gear 21 is rotatably supported by a large-diameter bearing 22 provided between the outer peripheral portion of the large gear 21 and the support plate 16.

Further, as the rotating mechanism of the cutter, as shown in FIG. 1 (c), the pinion 20 provided on the motor shaft of the cutter driving motor 19 is provided on the inner peripheral side of the rotating portion 21A as well as the above-mentioned structure. It may be one that meshes with the internal gear 21b attached to the.

In this case, the large gear 21 meshes with the other large gear 21 'having the same pitch circle diameter, and the cutters 3, 3'tune in such a manner that they rotate in opposite directions and at the same speed. I do. However, for example, when the shield machine is excavating in the ground and one cutter hits an obstacle in the ground (large rake etc.) and the rotation of the cutter suddenly stops, the required torque to rotate the cutter is In order to act on one tooth of the large gear 21, 21 ', its material, tooth width, thickness, etc. must be such that the tooth has sufficient strength.

At this time, in the case of FIG. 1A, since the cutter rotating gear simultaneously has a function of synchronizing the rotations of the cutters 3 and 3 ', the gear manufacturing precision is very high and the strength needs to be increased. Therefore, it is difficult to manufacture and costly. However, in the case of FIG. 1 (c), the gear 21b for turning the cutter and the large gear 21 for rotation tuning are separate bodies, so the large gears 21, 21 'for rotation tuning need to have sufficient strength. However, as for the accuracy of the gear, the cutter 3, 3 '
Since the gears do not have to collide with each other, precise gear machining is not particularly required for manufacturing the gear, and gear manufacturing is particularly economical.

Reference numeral 23 is a sealing material, which is a rotary partition wall 15 and an outer peripheral partition wall 14.
It is provided between and to prevent dirt and the like from entering the rotating mechanism. Since the support / rotation mechanism of the other rotary cutter 3'is also the same, detailed description thereof will be omitted by giving corresponding reference numerals. Then, when the cutter driving motors 19 and 19 'are driven, the rotations thereof are the pinions 20 and 20', the large gears 21 and 21 ', and the rotating portion 21 respectively.
It is transmitted to the rotary partition walls 15 and 15 'through a, 21a' and the like, and the rotary cutters 3 and 3'are rotated respectively.

In this case, the cutter bodies of the rotary cutters 3 and 3'are arranged with a phase difference of approximately 90 degrees, and the drive motors 19 and 19 'are arranged in opposite directions.
The large gears 21 and 21 'are meshed with each other at the central portion A, and both cutters are rotated at the same speed.

It is not always necessary that the large gears 21 and 21 'are meshed with each other at the central portion A. For example, by electrical control, both rotary cutters 3 and 3'have almost the same speed in opposite directions. You may make it rotate by. Further, the distance between the centers of the adjacent rotary cutters 3 and 3'is set to be longer than the larger radius of both radii and shorter than the sum of both radii. In addition, in order to prevent the rotating cutters 3 and 3 ′ from contacting each other, the central angle of the sector of the cutter body must be less than a certain angle, which is usually the radius and center of the cutter. It is determined by the ratio of the distances, and it is better to set it to a value between 40 ° and 90 °.

Further, 24 is a screw conveyor provided inside the mine, a screw driving motor 25 is provided at the rear end, and the front end 24a is connected to the outer peripheral partition wall 14 located near the constricted portion of the shield cylinder 1, The mud or the like in the face mud chamber 2 is taken into the screw conveyor and discharged by driving the screw driving motor 25. In addition,
Although the number of screw conveyors is one in the figure, the number of screw conveyors is not limited to one, and a plurality of screw conveyors can be installed. Reference numeral 26 is an oil jack, the front end of which is a supporting portion 1b which is erected on the inner wall surface of the shield cylinder 1, and the rear end of which is a reaction force receiving member.
Abutted on 27.

In order to keep the pressure of the mud filled in the face mud chamber 2 constant, the oil jack 26 is driven in consideration of the amount of mud discharged from the screw conveyor 24 to move the shield cylinder 1 forward. . In this case, the earth pressure of the mud in the face mud chamber 2 is the outer peripheral partition wall 14 facing the face mud chamber 2.
It is detected by the earth pressure gauge 28 provided in the.

The excavated soil of the face to be excavated by the two rotary cutters 3 and 3'is taken into the face mud chamber 2, and the excavated soil is mixed with the nature of the face (moisture content, plastic flowability). , Impermeable, etc.) Swivel joints 29, 29 'provided at the rear ends of the center shafts 6, 6', mud soil material injection pipes 30, 30 ', etc., in order to muddy the soil. Mud soil material is injected from the outside through this mud soil material injection pipe 5, 5'inside the center shaft 6, 6 '.
It is injected from the tip end to the outside.
Needless to say, this type of mud-making earth material injection pipes 5 and 5'may be provided at appropriate locations on the partition wall 13 or at appropriate locations on the spokes 8a and 8b.

Next, the operation of the present invention will be described. Now, when the drive motors 19 and 19 'are rotated, the two rotary cutters 3 and 3'are respectively moved to the pinions 20 and 2'.
One is rotated in the clockwise direction and the other is rotated in the counterclockwise direction in a state in which the phases are shifted by approximately 90 degrees through 0 ', the large gears 21, 21', etc., and the face of natural ground is excavated. In this case, the rotary cutter 3, 3 '
Since the cutter body has a substantially fan shape and a large number of bits 9 and 9'are provided in the outermost peripheral portion, it is possible to efficiently excavate the natural ground.

Since the excavated face soil enters the face mud chamber 2, if the ground is a sandy soil layer such as a sand layer or a gravel layer at this time, the mud soil material injection pipes 5 and 5'are used to supply the mud. Room 2
For example, bentonite, CMC aqueous solution or the like, or a mud soil material such as an air entraining agent mixed with foam is injected, and the excavated sand and sand that has entered the mud chamber 2 is mixed with the injected mud soil material. Mixing by rotating the mixing blades 10, when the mud soil material is the former, it has a unit weight almost the same as the ground of the face and has a water content ratio similar to that of the ground, and has plastic flowability and impermeable water. Converts to mud with nature. When the ground is a cohesive soil layer such as a silt layer or a clay layer, the required mud can be produced by mixing with the mixing blade 10 without using the above-mentioned mud-making soil material.

Since the mud chamber 2 is filled with the above-mentioned mud,
The earth pressure gauge should be adjusted so that the earth pressure of this mud becomes equal to the earth pressure of the face.
While monitoring by 28, by limiting the thrust of the shield outer cylinder 1 by driving the oil jack 26 and the discharge amount of mud by the screw conveyor 24, the face mud chamber 2
The earth pressure of the can be controlled to a constant pressure and the collapse of the face can be effectively prevented.

When the excavation of the face is advanced in this manner, the mud in the face mud chamber 2 is successively taken into the rear screw conveyor 24 in a filled state. Therefore,
The mud taken in is discharged to the outside from a carry-out port (not shown) provided behind the screw conveyor 24. Then, in the excavated side shaft, the excavated cross section, that is, a segment (not shown) that is slightly smaller than the outer shape of the shield outer cylinder 1 and is assembled and has a cocoon-shaped or dharma-shaped cross section is formed in the shield outer cylinder 1. It is possible to construct sideways with a desired shape by sequentially assembling them on the rear end side.

FIG. 2 shows a second embodiment of the present invention.
This embodiment differs from the above-mentioned embodiments in that the cutter bodies of the rotary cutters 3 and 3'are fan-shaped in the form of a face plate extending in the radial direction from the bearings 7 and 7'in the central portion.

FIG. 3 shows a third embodiment of the present invention, in which the cutter body of each rotary cutter 3, 3'supports an arcuate member 31 with one spoke 32, and a bearing at the center. It is characterized in that it is formed in a shape similar to a fan shape having a spread in the outermost peripheral portion when viewed from 7, 7 '. In addition, in these embodiments, other configurations, operations and the like are similar to those of the first embodiment.

FIG. 4 shows a fourth embodiment of the present invention in which the rotating mechanism of the rotary cutters 3 and 3'is different from the first embodiment. In this embodiment, the rotary partition located inside the outer peripheral partition 14 is ring-shaped. The partition walls 15a and 15a 'are used to form the partition walls 15a and 15a.
a'and the rotary cutters 3, 3'include the cutter support beam 18
It is connected with. In addition, each center shaft 6, 6 '
Are located inside ring-shaped partition walls 15a, 15a 'and have a circular shape, and are fixed via a support plate 16 to partition walls 15b, 15a.
They are axially supported by b'via seals and bearings 17, 17 '. The configurations of the cutter driving motors 19 and 19 'for rotating the partition walls 15a and 15a', the pinions 20 and 20 ', the large gears 21 and 21', and the bearings 22 and 22 'are the same as those in the first embodiment.

FIG. 5 shows a fifth embodiment of the present invention.
In this embodiment, the bearings 7 of each rotary cutter 3, 3 ',
As in the first embodiment, the cutter body including the center bits 4 and 4'provided at the tip of the 7'cutter support beam 1
8. The rotary partition walls 15 and 15 'are respectively driven, and the radially extending mixing blades 34 and 34' are provided on the outer peripheral portions of the center shafts 6 and 6 ', respectively,
Before and after these mixing wings 34, 34 ', mixing wings 35, 35'
And the center shafts 6, 6'are rotated via separate drive motors 36, 36 'and gear mechanisms 37, 37' to improve the mixing effect in the central portion. The kneading blades 34 and 35 are the cutter body and the rotary partition.
15 and 15 ', respectively, and the center shafts 6 and 6'are rotatably provided with respect to the bearings 7 and 7'.

FIG. 6 shows a sixth embodiment of the present invention, in which the first to fifth embodiments described above have two rotary cutters. In this embodiment, two or more rotary cutters are provided in the horizontal direction. An example in which rotary cutters 3 ... 3 ⁿ are provided is shown. In this case, it goes without saying that the shield cylinder 1 is also configured to accommodate the rotary cutters 3 ... 3 ⁿ therein. Further, as the drive mechanism of each rotary cutter 3 ... 3 ⁿ , the optimum one of the above-mentioned embodiments is combined. It should be noted that the positional relationship among the rotary cutters 3 ... 3 ⁿ is not necessarily limited to the horizontal direction, and may be the vertical direction or even the diagonal direction. Also, the radius of each rotary cutter is
As shown in FIG. 7, they may be different, and when the number of rotary cutters is three or more, their centers may not all be on a straight line.

Although the shield machine of each of the above embodiments is of earth pressure type, the cutter of the present invention can be applied to a mechanical shield machine such as an open mechanical shield or a mud pressure shield. Of course.

[0032]

As described above, according to the present invention, since the cutter body is formed in a shape similar to that of a fan and a large number of bits are provided at the outermost periphery where the excavation is the most severe, the strength of the cutter body is improved. Further, the durability is improved, and even in the case of long-distance excavation or gravel layer excavation, there is an advantage that bit exchange is reduced or unnecessary, so that time and cost can be saved.

[0033]

[Brief description of drawings]

FIG. 1 is a first embodiment of the present invention, in which (a) is a cross-sectional view for explaining the internal structure as seen from a plane, (b) is a front view of the same, and (c) is another form of a rotating mechanism. Here is an example.

FIG. 2 is a schematic front view of a second embodiment of the present invention.

FIG. 3 is the third embodiment.

FIG. 4 is a fourth embodiment of the present invention.

FIG. 5 is a fifth embodiment of the present invention.

FIG. 6 is a sixth embodiment of the present invention.

FIG. 7 is a seventh embodiment of the present invention.

FIG. 8 Conventional example

[Explanation of symbols]

 1 ... Shield tube 3, 3 '... Rotating cutter 9, 9' ... Bit

Front page continued (72) Kenji Okubo Inventor Kenji Okubo 1-24-4 Shinkawa Chuo-ku, Tokyo Within Daitoyo Construction Co., Ltd. (56) Reference JP-A-57-197395 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A shield excavator for obtaining an excavation cross-section having a shape in which a plurality of circles are adjacent to each other and a part of them are overlapped with each other, and a plurality of rotary cutters (3) for excavating each circle cross-section,
(3 ') is arranged on substantially the same plane, and the respective cutter bodies of the rotary cutters (3) and (3') have a substantially fan shape or a shape similar to that of the outermost peripheral shape with respect to the center thereof. And each cutter body is arranged with a phase difference that meshes with each other in the rotation direction of the cutter body, and a large number of bits (9) for face excavation are also provided on the outermost periphery of each cutter body. (9 ') is provided, The shield excavator characterized by the above-mentioned.