JPH0213599Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an earth and sand conveying device for a shield excavator used in tunnel excavation work, and in particular relates to an earth and sand conveying device for a shield excavator used in tunnel excavation work, and in particular, a method for connecting multiple screw conveyors. This invention relates to an earth and sand conveying device for a shield excavator, which connects sections with bendable universal pipe joints to enable earth and sand to be conveyed through curved sections of a tunnel.

[Conventional technology] A shield tunneling machine is used as a construction method for constructing tunnels, etc., and a hole is formed while excavating the excavated surface with the cutter of the shield tunneling machine, and in parallel with the excavation, the tunnel is shielded with segments, etc. A shield construction method has been developed.

When excavating this tunnel, etc., the earth and sand excavated by the excavation machine,
The material is introduced into a cutter wheel installed inside the excavator, and transported from the cutter wheel to the outside (to the rear of the tunnel) by a screw conveyor. The amount of soil discharged by the screw conveyor is specified to be commensurate with the amount of excavation by the excavator.

By the way, conventionally, on the discharge end side of the screw conveyor, another screw conveyor is connected to the screw conveyor in order to further convey the excavated sand to an appropriate position behind the tunnel.
The delivery end of this screw conveyor was connected in series with the delivery end of another screw conveyor to form an earth and sand conveying device for a shield excavator that conveys excavated earth and sand.

In addition, since each screw conveyor that constitutes the above-mentioned earth and sand conveyor conveys excavated earth and sand that has different properties and sizes, such as clay, mud, rock, and gravel, the screw conveyor that forms the outer shell of the screw conveyor A drive motor is attached to one end of the tube, one end of a screw shaft installed inside these conveyor tubes is connected to the drive motor, and the screw shaft is connected between the outer edge of the screw blades attached to the screw shaft as a pair and the inner surface of the conveyor tube. The radial spacing was formed to allow some degree of axial runout.

This is achieved by attaching the screw shaft in a cantilevered manner to the conveying pipe and creating a radial interval between the outer edge of the screw blade and the inner surface of the conveying pipe that allows for some degree of axial wobbling of the screw shaft. When conveying large gravel, etc., the screw shaft is oscillated appropriately to enable the conveyance, and when conveying relatively small-sized earth and sand, the axial vibration of the screw shaft is automatically suppressed by the rotational support of the earth and sand. It is intended to be corrected. Therefore, it becomes possible to smoothly transport excavated soil having different properties and sizes, such as clay, mud, rock, and gravel.

By the way, due to construction plans for tunnels, etc. and plan changes during construction, etc., it is often required to form curved holes vertically and horizontally in the tunnel construction route, and as a result, the connection part of the screw conveyor, which is the earth and sand transport device, is There was a need for a structure that could be bent freely depending on the situation. Therefore, as shown in FIGS. 1 and 2, first and second screw conveyors 1 and 2 each having screw shafts 6a and 6b installed therein,
The output end and the input end of the screw shaft 6a are connected to each other by an expansion joint 7 in a flexible manner, and the screw shaft 6a,
The earth and sand conveying device was constructed by accommodating the carrying-out end and carrying-in end of 6b. Then, the output end of the screw shafts 6a, 6b is placed between the output end and the input end of the screw shafts 6a, 6b in accordance with the maximum bending angle of the expansion joint 7. A space is formed between the carry-in end and the screw blades of the screw shafts 6a, 6b to avoid contact with each other. The expansion joint 7 is configured by forming spiral folds that project outward in the radial direction at predetermined intervals in the axial direction, and exhibits good stretchability and flexibility. . As a result, even during the above-mentioned bending construction, the excavated earth and sand can be transported to the rear of the tunnel.

[Problem to be solved by the invention] However, when the expansion joint 7 is bent, the ends of the screw shafts 6a, 6b inside the expansion joint 7 are
At this time, the screw blades of the screw shafts 6a, 6b may come into contact with the inner surface of the expansion joint 7 and damage the inner surface of the expansion joint 7. A problem occurs.

Conventionally, this problem was dealt with by reducing the diameter of the screw blade installed in the expansion joint 7 in accordance with the maximum bending angle, but this configuration reduced the transport efficiency of the earth and sand. Not only that, but the diameter of the screw blade had to be made smaller as the bending construction angle of the tunnel became larger, which naturally led to a limit.

Note that there is a known proposal for a ``combine harvester unloader connection device'' (Japanese Utility Model Publication No. 18215/1983) in which the connecting ends of screw conveyors are connected to each other by a bendable universal pipe joint. This proposal is based on a screw shaft housed in a conveyor tube and a conveyor tube that connects two conveyors in a flexible manner with a universal joint, in order to convey grain of almost constant grain size without sacrificing quality. It is necessary to keep the axes of the screw shafts aligned at all times, and the opposing shaft ends of the screw shafts are connected to each other with a universal joint. However, if the screw shaft ends are connected in this way, it becomes difficult to transport soil with different properties and sizes, such as clay, mud, rocks, gravel, etc., and this can cause damage to the transport pipe and screw. It is difficult to adopt this method because of the possibility that the transport resistance may increase abnormally.

The purpose of this invention is to smoothly bend the joints between the screw conveyors according to the degree of bending of the curved section when using a shield excavator to construct a curved section, and to efficiently transport excavated earth and sand to the rear of the tunnel. An object of the present invention is to provide an earth and sand conveying device for a shield excavator.

[Means for Solving the Problems] In order to achieve the above object, the present invention rotatably accommodates a screw shaft having an axial length appropriately longer than that of the transport pipe in a transport pipe, and connects one end of the screw shaft to the transport pipe. A shield excavator that connects to a drive motor attached to one end to form a screw conveyor, and connects the other ends of the screw conveyor with a flexible joint to change the conveyance direction of excavated earth up, down, left, and right. In this earth and sand conveying device, the other ends of the conveying tubes are connected to each other by an inner tube having a convex spherical surface on the outer peripheral surface with the center of the spherical surface located on the axis of one of the conveying tubes, and an inner tube having a convex spherical surface on the inner peripheral surface that is connected to the spherical part. and an outer tube formed with a concave spherical surface that fits freely around the center and is connected by a universal joint, and the pipe length of this universal joint is set between the opposing screw shaft ends at the maximum length of the pipe joint. The tube length is formed to avoid contact between the shaft ends at the bent position, and an enlarged diameter portion is formed on the concave spherical surface at that position to avoid contact with the outer edge of the screw blade within the convex spherical surface.

[Operation] When the drive motor attached to one end of the conveyor pipe is rotated, the excavated soil introduced into the conveyor pipe is sequentially moved from one end to the other by the screw blades of the screw shaft, and flows inside the universal pipe joint. It passes through and is supplied into another conveying pipe. The screw blades in the other conveying pipes sequentially convey the supplied excavated earth and sand. If large stones, gravel, etc. are mixed into the excavated soil during this transportation process, each screw shaft in each conveying pipe will swing out appropriately, allowing the large stones, gravel, etc. to be transported without resistance. . After the stones and gravel have been discharged, each screw blade is smoothly supported for rotation by the excavated earth and sand that is being conveyed. In other words, unlike the above-mentioned conventional example (publication of Utility Model Publication No. 18215-1973) in which grains of a certain size (grain size) are transported, clay,
To satisfactorily transport earth and sand of different properties and sizes, such as mud, rocks, and gravel, and there is no risk of damaging transport pipes or screws or abnormally increasing transport resistance during transport.

When a hole is changed from a straight line to a curved hole, the flexible pipe joint is bent to match the bending angle of the curved hole, thereby bending the joint between the screw conveyors.
That is, in the universal joint, the concave spherical surface of the other outer tube rotates in a bending direction with respect to the convex spherical surface of the inner tube whose center is placed on the axis of one conveying tube. At the maximum bending position of the conveying pipes, the length of the universal joint is such that the ends of the pipe joints are prevented from coming into contact with each other between the opposing screw shaft ends, and the concave spherical surface is formed with a convex spherical surface at that position. As a result of forming an enlarged diameter portion that avoids contact with the outer edge of the screw blade, it is structurally possible to prevent contact between the screw shaft ends and the screw blades, as well as contact between the outer edge of the screw blade and the inner and outer tubes at maximum bending. be done.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, the shield excavator 11
The earth and sand excavated by the shield excavator 11
The earth and sand is sent to an appropriate position within the tunnel 10 by the earth and sand conveying device 12 of the shield excavator attached to the earth and sand, and is carried out from there to the outside of the tunnel 10.

Hereinafter, the relationship between the shield excavator 10 and the earth and sand transport device 12 of the shield excavator will be specifically explained.

As shown in FIG. 3, the shield tunneling machine 11 has a cylindrical cutter wheel 13 and a cutter wheel 1.
The front part of the cutter wheel 13 is closed and provided with a rotary cutter part 14 for excavating the excavated surface, and the inside of the cutter wheel 13 is partitioned with an appropriate interval from the rotary cutter part 14 to the rear side of the cutter wheel 13, and excavated earth and sand are separated. a cutter frame 15 for partitioning and forming a cutter chamber 33 for taking in the cutter frame 15; and a screw conveyor 16 for carrying out earth and sand, which is provided at an angle above the tunnel 10, the carrying end of which is inserted into the lower side of the cutter frame 15. It mainly consists of. The screw conveyor 16 substantially forms a cutoff wall for the excavated earth and sand within the screw conveyor 16 by the transported earth and sand.
The screw conveyor 16 includes a conveying pipe 17 having an annular cross section, a screw 6c that is installed inside the conveying pipe 17 to convey earth and sand, and a discharge end 5c of the conveying pipe 17.
It is comprised of a hydraulic motor 18 that is connected to the screw 6c and transmits driving force, and a universal pipe joint 20 that is attached to the discharge port 19 on the discharge end 5c side. A discharge port 19 for discharging the transported earth and sand is formed at the discharge end side of the transport pipe 17.

Now, as shown in FIGS. 3 and 4, the earth and sand conveying device 12 for conveying the earth and sand discharged from the discharge port 19 to the rear of the tunnel consists of first and second screw conveyors 1 and 2, and these conveyors. and a flexible pipe joint 11 that connects the pipes in a flexible manner.

The first screw conveyor 1 includes a conveying pipe 3a having an annular cross section, an internal structure extending from an inlet end 4a to an outlet end 5b of the conveyor tube 3a, and a conveyor pipe 3a having an annular cross section.
A screw shaft 6a for transporting earth and sand protrudes from the transport pipe 3a at a predetermined distance from the transport pipe 3a, and the transport end 4.
The drive motor 18 is attached to the screw shaft 6a with its carry-in end closed, and connected to one end of the screw shaft 6a to rotationally drive the screw shaft 6a.
The drive motor 18 is constituted by a hydraulic motor in the embodiment. Conveying pipe 3 of first screw conveyor 1
A has an input port 23 formed on its carry-in end 4a side. The input port 23 and the discharge port 19 are connected by a universal joint 20. The second screw conveyor 2 is constructed in substantially the same way as the first screw conveyor 1. That is, the hydraulic motor 18 is connected to the discharge end 5a of the second screw conveyor.
is attached, and furthermore, a discharge port 24 is opened on the discharge end 5a side of the second screw conveyor 2. A screw shaft 6b installed inside the conveying tube 3b also projects from the carry-in end 4b of the conveying tube 3b to the outside of the conveying tube 3b by a predetermined distance.

As shown in FIG. 4, the universal joint 11 includes an inner tube 21 having a convex spherical surface 30 formed on its outer circumferential surface with its center on the axis of one of the conveying tubes 3a, and an inner tube 21 having a convex spherical surface 30 on its inner circumferential surface. an outer tube 22 formed with a concave spherical surface 31 that engages with the spherical surface 30 and fits freely around the center;
It consists of

On the other hand, the conveying pipe 3 of the first screw conveyor 1
A flange 25 is provided on the outer periphery of the delivery end 5b of the conveyor pipe 3b of the second screw conveyor 2 and the delivery end 4b of the transport pipe 3b of the second screw conveyor 2.
and is flange-connected to the outer tube 22. A seal ring 29 is attached at an appropriate position on the circumferential surface of the concave spherical surface 30 to prevent earth and sand from being discharged to the outside of the universal joint 11 when the outer tube 22 and the inner tube 21 are fitted together. As shown in FIG. 4, an end 26 of the screw shaft 6a on the discharge end 5b side of the first screw conveyor 1 and an end 27 of the screw shaft 6a on the carry-in end 4a side of the second screw conveyor 1. Even when the universal joint 11 is bent to the maximum, the ends 26, 27
The end portions 26 and 27 are formed with a length having a predetermined distance in the axial direction so that they do not come into contact with each other. The screw blade 28 inside the convex spherical surface 30 is located on the concave spherical surface 31 at the maximum bending angle position of the conveyor tubes 3a, 3b.
In order to avoid contact with the outer edge of the concave spherical surface 3
1 is expanded in diameter outward in the radial direction to form an expanded diameter portion 32. When the end portions 26 and 27 are spaced apart from each other and the enlarged diameter portion 32 is formed in this way, even if the convex spherical surface 30 is rotated relative to the concave spherical surface 31, the ends of the screw shafts 6a and 6b Parts 27 and 28 mutually,
And, the screw blades 28, 28 are brought into contact with each other, and the screw blades 28, 28 and the inner tube 21 are brought into contact with each other.
contact with the inner surface of the outer tube 22 and the inner surface of the outer tube 22 is prevented.

Hereinafter, the operation of the embodiment of the present invention will be explained.

As shown in FIG. 3, the earth and sand excavated by the shield excavator 11 is taken into the cutter wheel 13, conveyed by the screw conveyor 16, and passed from the discharge port 19 via the universal pipe joint 20. It is dropped into the input port 23 of the transport pipe 3a.

When the hydraulic motor 18 attached to one end of the conveyance pipe 3a is rotated, the excavated earth and sand introduced into the conveyance pipe 3a is moved by the screw blade 2 of the screw shaft 6a.
8, it is sequentially moved from the other end side, that is, from the carry-in end side to the other end side, passes through the inside of the universal pipe joint 11, and is supplied into the other conveyance pipe 3b. The screw blades 28 in the other conveyance pipe 3b sequentially convey the supplied excavated earth and sand to the discharge end side. If large stones, gravel, etc. are mixed into the excavated soil during this conveyance process, each screw shaft 6 in each conveyance pipe 3a, 3b
a and 6b cause appropriate shaft vibration and convey the large stones, gravel, etc. without resistance. After the stones and gravel have been discharged, the screw blades 28, 28 are smoothly supported in rotation by the excavated earth and sand being conveyed. 1st
The excavated earth and sand conveyed from the screw conveyor 1 to the second screw conveyor 2 is discharged to the slurry trolley 30 or the like at the rear of the tunnel. In this way, unlike the above-mentioned conventional example (publication of Utility Model Publication No. 18215/1973), in which grains of a certain size (particle size) are transported, this method can transport grains of various properties and sizes, such as clay, mud, rock, gravel, etc. Different types of earth and sand can be transported well, and there is no risk of damaging the transport pipe or screw or abnormally increasing transport resistance during transport.

On the other hand, the enlarged diameter portion 32 is located at the bent position shown by the two-dot chain line in FIG.
A relief interval is formed to prevent the outer edges of the tubes 8 and 28 from coming into contact with the inner surface of the inner tube 22. It goes without saying that the volume of the enlarged diameter portion 32 is determined in accordance with the maximum bending angle of the universal tube joint 11. Furthermore, even if the screw shafts 6a and 6b should rotate eccentrically, the inner tube 21 and the outer tube 22 are made of steel, so that sufficient safety with respect to wear resistance is provided.

As a result, the earth and sand transport device 11 of the shield excavator
It can be bent freely, making it possible to construct curved sections freely.

In the above embodiment, the inner tube 21 is connected to the conveying tube 3a, and the outer tube 22 is connected to the conveying tube 3b by a flange, but the reverse may be used. In addition, the inner pipe 21 and the outer pipe 2 for the conveying pipes 3a and 3b
2 may be connected by welding.

Further, the structure that is bent by fitting the inner tube 21 and the outer tube 22 is not limited to applications such as connecting the first and second screw conveyors 1 and 2; for example, the shield excavator 11 When using a pressure pump such as a concrete pump to pump earth and sand carried out from Fittings can be used.

[Effects of the invention] As described above, the present invention provides the following excellent effects.

The screw conveyors are connected to each other with bendable flexible pipe joints, and one end of the screw shaft in the conveyor tube that constitutes each screw conveyor is connected to a drive motor attached to one end of the conveyor tube, and each screw shaft is rotated to prevent axial runout. Because of this structure, when transporting large stones, gravel, etc., it is facilitated by the axial vibration of each screw shaft, and after the transport of stones and gravel is completed, the rotational resistance (support reaction force) of the excavated soil against the screw is reduced. This allows the screw to have a self-centering function. In tunnel bending construction, within the maximum bending range of the universal pipe joint, contact between the opposing screw shafts and contact between the screw blades is prevented, and contact between the outer edge of the screw blade and the inner surface of the inner pipe, and the screw By preventing contact between the outer edge of the blade and the inner surface of the outer tube, wear on the screw blade, inner tube, and outer tube can be suppressed, and excavated earth and sand can be transported smoothly in the tunnel.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view showing a conventional example in which an expansion joint is used in the connection between two screw conveyors, which are the earth and sand conveying device of a shield excavator, and Figure 2 is a diagram showing a bent expansion joint. Fig. 3 shows a state in which a tunnel is being excavated using a shield tunneling machine, and a connection part between two screw conveyors installed in the tunnel, which has a convex spherical surface according to the present invention. A diagram showing a state in which an inner tube and an outer tube having a concave spherical surface that fits into the inner tube are joined together in a flexible manner. FIG. FIG. 3 is a detailed cross-sectional view of a main part showing a connection state between an outer pipe having an outer pipe and each screw conveyor. In the figure, 1 and 2 are screw conveyors, 3a and 3
b is a conveying tube, 6a and 6b are screw shafts, 18 is a drive motor, 21 is an inner tube, 22 is an outer tube, 30 is a convex spherical surface, 31 is a concave spherical surface, and 32 is an enlarged diameter portion.

Claims (1)

[Scope of utility model registration request] A screw shaft having an appropriately longer shaft length than the transport pipe is rotatably accommodated in the transport pipe, and one end of the screw shaft is connected to a drive motor attached to one end of the transport pipe to form a screw conveyor. In the earth and sand transport device for a shield excavator, the other ends of the transport pipe are connected to each other with a flexible joint to change the transport direction of the excavated earth to up, down, left and right. Consists of an inner tube formed with a convex spherical surface with the center of the spherical surface on the axis, and an outer tube formed with a concave spherical surface on the inner circumferential surface that engages with the spherical surface and bends freely around the center. They are connected by a universal joint, and the pipe length of the pipe joint is formed to a length that avoids mutual contact between the opposing screw shaft ends at the maximum bending position of the pipe joint, and the concave spherical surface is connected at that position. An earth and sand transport device for a shield excavator, characterized in that an enlarged diameter portion is formed to avoid contact with the outer edge of a screw blade within a convex spherical surface.