JPH05187192A - Earth removing method for screw conveyor - Google Patents

Abstract

PURPOSE:To perform an excavation in the stable state even when the earth water pressure in the cutter chamber of an earth pressure type shield machine is sharply changed. CONSTITUTION:When the sediment in the cutter chamber 9 of an earth pressure type shield machine 1 is to be discharged with a screw conveyor 21, screw blades 27 are removed from a rotary shaft portion 25A located near an earth removing port 31, and a bladeless space section 35 with the preset length where only a rotary shaft 25 is located is provided in a casing 23. The earth removing port 31 is moved along the longitudinal direction of the casing 23 in response to the earth water pressure in the cutter chamber 9, and the length L1 of the sand plug zone 51 formed by the bladeless space section 35 on the upstream of the earth removing port 31 is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil discharging method for a screw conveyor.

[0002]

2. Description of the Related Art A screw conveyor is generally a cylindrical casing having a soil inlet and an outlet, a rotary shaft disposed inside the casing, and a screw attached to the rotary shaft. The blade is provided, and earth and sand are transferred in the casing by rotation of the rotating shaft. The screw conveyor is used, for example, in the earth pressure type shield construction method to discharge the excavated earth and sand filled in the cutter chamber of the shield machine.

As a screw conveyor of this type, there is known one in which a screw blade is removed from a rotary shaft portion near the soil discharge port and a sand plug zone in which only the rotary shaft is located is provided upstream of the soil discharge port. The sand plug zone utilizes the water blocking effect by compaction of earth and sand to give an appropriate resistance to earth water pressure in the cutter chamber. Like the total length of the screw conveyor, the length of this sand plug zone is pre-determined in consideration of the soil quality, expected face water pressure, and earth pressure, and is unchanged, but the resistance force due to the sand plug zone is the opening of the soil discharge port. It can be adjusted within a predetermined range by changing the area. Therefore, when the soil water pressure in the cutter chamber changes, the resistance of the sand plug zone is conventionally changed by changing the opening area of the soil discharge port to stabilize the cutting face.

[0004]

However, when the soil water pressure in the cutter chamber changes greatly in the ground where gravel and the like are mixed, it is only necessary to adjust the opening area of the soil discharge port to change the resistance force by the sand plug zone. I can not handle it,
There was a problem that we could not dig in a stable state. The present invention has been devised in view of the above circumstances, the object of the present invention is a screw conveyor that can be excavated in a stable state even when the soil water pressure in the cutter chamber is greatly changed in the ground where gravel and the like are mixed. To provide a method of soil removal in.

[0005]

In order to achieve the above object, the present invention provides a casing having a soil inlet and a soil outlet,
When excavating with a screw conveyor consisting of a rotating shaft arranged inside the casing and a screw blade attached to the rotating shaft, the screw blade is removed from the rotating shaft portion located near the earth discharging port, and the casing Provide a bladeless space of a predetermined length in which only the rotating shaft is located,
Move the soil discharge port along the longitudinal direction of the casing,
It is characterized in that the length of the sand plug zone formed in the bladeless space upstream of the soil discharge port is changed.
Further, the present invention is characterized in that the earth and sand inlet is arranged in a cutter chamber of an earth pressure type shield machine, and a length of the sand plug zone can be changed according to earth water pressure in the cutter chamber. ..

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic side view of a shield machine and a screw conveyor in use. 1 is earth pressure type shield machine, 3 is fish tail, 5 is cutter wing, 7 is kneading blade,
9 is a cutter chamber, 11 is a motor for driving a cutter, 13 is a shield jack, 15 is a center-folding jack,
17 is an erector, 19 is a segment, 21 is a screw conveyor, and the screw conveyor 21 is disposed with its tip penetrating inside the cutter chamber 9,
The excavated earth and sand in the cutter chamber 9 is transferred rearward by the screw conveyor 21, and further, the excavated earth and sand is transferred rearward by a belt conveyor (not shown).

The screw conveyor 21 is a casing 23.
And a rotary shaft 25 and a screw blade 27. The casing 23 is cylindrical and has a predetermined length. An inlet 29 for earth and sand is formed at one end of the casing 23 in the longitudinal direction, and an outlet 31 is provided at the other end. The inlet 29 is located in the cutter chamber 9, and the casing 2 on the soil discharge port 31 side
The driving machine 33 is attached to the three ends. Rotating shaft 25
Is disposed coaxially with the casing 23 inside the casing 23, and is rotationally driven by a driving machine 33. The screw blade 27 is spirally wound around the rotary shaft 25, and its outer diameter is formed to have a size facing the inner peripheral surface of the casing 23. The screw blade 27 is removed from the rotary shaft portion 25A near the soil outlet 31 over a predetermined axial length, and the bladeless space 35 is formed in the casing 23 by this portion 25A.

As shown in FIG. 2, an opening groove 37 extending along the longitudinal direction of the casing 23 is formed in the lower portion of the casing 23 forming the bladeless space 35, and the opening groove 37 is formed. Guide grooves 39 that face each other and extend along the longitudinal direction of the opening groove 37 are formed on both sides of the guide groove 39. A slide plate 41 having a length about twice the length of the opening groove 37 is slidably coupled to the guide groove 39. Further, the hole 4 is formed in the center of the slide plate 41 in the longitudinal direction.
3 is provided, and an opening / closing valve 45 is provided in communication with this hole 43. The on-off valve 45 is composed of a case 45A and a valve body (not shown), the case 45A is fixedly connected to the slide plate 41, and the opening degree of the valve body is adjusted by a hydraulic cylinder 47. The on-off valve 45 constitutes the soil discharge port 31.

A hydraulic cylinder 49 is attached to the lower portion of the casing 23, and a rod 49 of the hydraulic cylinder 49 is attached.
While the hydraulic cylinder 47 is attached to the base of A,
The slide plate 41 is connected to the tip of the rod 49A,
The slide plate 41 is expanded and contracted by the hydraulic cylinder 49.
The hydraulic cylinder 47 moves, and the soil discharge port 31 moves along the longitudinal direction of the casing 23.

Next, the operation will be described. When the rotary shaft 25 and the screw blades 27 are rotated by the driving machine 33 during tunnel excavation, the earth and sand in the cutter chamber 9 are scraped up. When the opening area of the soil discharge port 31 is adjusted by the hydraulic cylinder 47, the earth and sand are accumulated and filled in the bladeless space 35, and when the soil discharge amount becomes smaller than the scraped amount, the soil discharge amount becomes smaller than that in FIG. As indicated by the dotted line 3 in FIG. 3, a sand plug zone 51 is formed in the bladeless space 35 upstream of the soil discharge port 31. As a result, the sand and sand in the screw conveyor 21 is pressed and stably transferred, and A resistance force is applied to the soil water pressure in the cutter chamber 9.

When the soil water pressure in the cutter chamber 9 is high, the hydraulic cylinder 49 operates to remove the soil discharge port 3
1 is moved upward to increase the resistance by increasing the length of the sand plug zone 51, and when the soil water pressure is low, the soil discharge port 31 is moved downward to decrease the length of the sand plug zone 51. To reduce the resistance,
Reference symbol L1 indicates the length of the shortest sand plug zone 51, and reference symbol L2 in FIG. 3 indicates the longest sand plug zone 51.
Indicates the length of. Therefore, by giving an appropriate resistance force by the sand plug zone 51 to a change in earth water pressure in the cutter chamber 9, it is possible to keep the earth water pressure in the cutter chamber 9 at an appropriate value and excavate in a stable state. Becomes Furthermore, since the construction can be performed without narrowing the opening area of the soil discharge port 31, the excavation can be performed more stably. Further, the hydraulic cylinder 49 is provided with various sensors for detecting soil quality, water pressure, and earth pressure in the cutter chamber 9, and can be controlled using a microcomputer or the like based on the detection results of these sensors. It is possible to automatically and sequentially change the length of the sand plug zone 51 according to the soil water pressure inside 9.

Although the screw conveyor 21 used for soil discharge in the mud pressure shield construction method is applied in the embodiment, the use of the screw conveyor of the present invention is not limited to this and is arbitrary.

[0013]

As is apparent from the above description, according to the present invention, a bladeless space portion having a predetermined length is provided near the soil discharge port, in which only the rotating shaft is located, and the soil discharge port is formed in the longitudinal direction of the casing. The length of the sand plug zone formed in the bladeless space upstream of the soil discharge port was changed so that it can be used in the earth pressure type shield construction method in the ground with mixed gravel. Even if the soil water pressure in the cutter chamber changes significantly, it is possible to excavate in a stable state.

[Brief description of drawings]

FIG. 1 is a schematic side view of a usage state of a screw conveyor, showing a state in which the length of a sand plug zone is set to be the shortest.

FIG. 2 is a sectional view of an opening groove and a slide plate portion.

FIG. 3 is a schematic side view of a usage state of the screw conveyor, showing a state where the length of the sand plug zone is set to be the longest.

[Explanation of symbols]

 1 Earth Pressure Shield Machine 9 Cutter Chamber 21 Screw Conveyor 23 Casing 25 Rotating Shaft 27 Screw Blade 29 Earth and Sand Inlet 31 Exhaust Exit 35 Bladeless Space 51 Sand Plug Zone

Claims (2)

[Claims] 1. When discharging soil by a screw conveyor comprising a casing having a sand and sand inlet and a soil discharging port, a rotary shaft arranged inside the casing, and screw blades attached to the rotary shaft, Remove the screw blade from the rotary shaft portion located near the soil discharge port, provide a bladeless space of a predetermined length in the casing where only the rotary shaft is located, and move the soil discharge port along the longitudinal direction of the casing. Let
An earth discharging method for a screw conveyor, wherein a length of a sand plug zone formed in a bladeless space upstream of the earth discharging port is changed. 2. The screw according to claim 1, wherein an inlet of the earth and sand is arranged in a cutter chamber of an earth pressure type shield machine, and a length of the sand plug zone is changed according to earth water pressure in the cutter chamber. How to remove soil on a conveyor.