JPS593637B2 - Closed type shield excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a closed type shield excavator that is applied to geological formations that are prone to collapse, such as soft geological formations and sandy layers containing groundwater.

Conventionally, in this type of shield excavator, an outer cutter disk is rotatably attached to the front opening of the cylindrical shield body, and the earth and sand excavated by the outer cutter disk is taken into the cutter disk and transported by a belt conveyor or the like. It is configured to be carried out to the rear of the shield tunneling machine.

By the way, since the rear part of the Outakatsuta disc is open, if the ground to be excavated has a high moisture content and is highly collapsible, natural inflow of earth and sand into the face cannot be prevented, causing the ground to collapse. At the same time, the shield tunneling machine may be filled with earth and sand, and the tunnel excavation work may have to be interrupted. A mechanical method to solve this problem is to adjust the amount of soil taken in by the outer cutter disk, but conventionally, adjusting the amount of soil taken in is done by making the opening of the outer cutter disk have a slit structure that matches the soil quality. The situation is almost impossible. The first invention was made to improve the above-mentioned drawbacks, and includes an inner vine disk that is provided in the shield body behind the outer vine disk facing the face, and spreads out to the front side between these two disks. As a configuration with an internal cone plate,
The rear space in the outer cutter disc facing the face is constantly pressurized and filled with excavated soil to prevent natural inflow of earth and sand into the face.
To provide a closed type shield excavator capable of excavating a tunnel while preventing the front part of the shield from collapsing that would reach the ground level.

Furthermore, in addition to the object and structure of the first invention, a second invention provides that, in addition to the object and structure of the first invention, in the rear cylinder of the inner cutter disk,
A scraping plate for the excavated soil is installed, and a screw conveyor is passed through the excavated soil in a liquid-tight manner, and the excavated soil is scraped up by the scraping plate, placed on the screw conveyor, and smoothly discharged to the outside. With the goal.

Hereinafter, embodiments including the second invention and the second invention will be described with reference to the drawings.

In the figure, 1 is a cylindrical shield main body, 2 is an outer cutter disk rotatably attached to the front opening of the shield main body 1, and this disk 2 includes a front plate 3, a cylindrical body 4, and a circumferential rear plate 5. The front plate 3 is provided with a blade 6 and an opening 7 for the inflow of the material to be excavated.

The outer cutter disk 2 includes a radial bearing 8, a thrust bearing 9, and a seal member 1 installed in the shield body 1.
0, and is set in the shield body 1 so as to be rotatable and fluid-tightly sealed between the shield body 1 and the shield body 1. 11
A cone plate is fixed within the outer cutter disk 2 and rotates integrally therewith, and 12 is a sub-cone plate.

An inner cutter disk 13 is rotatably mounted within the shield body 1 facing the rear opening of the corn play port 1,
This inner cutter disk 13 includes a front plate 14 and a cylindrical body 1.
5 and an encircling rear plate 16, the front plate 14 is provided with a blade 17 and an opening 18 for inflow of soil to be excavated, and the cylindrical body 15 is provided with a scraping plate 15a. The inner cutter disk 13 is rotatable by a radial bearing 19, a thrust bearing 20, and a seal member 21 installed in the outer cutter disk 2, and is liquid-tightly sealed between the inner cutter disk 13 and the outer cutter disk 2. is set within. A screw conveyor 22 passes through the inner cutter disk 13 from the rear, and a sealing member 24 is inserted between a fixing plate 23 attached to the screw conveyor 22 and the circumferential rear plate 16.

Drive rings 25 and 26 are attached to the rear ends of the outer cutter disk 2 and the inner cutter disk 13, and a drive motor 2 such as a hydraulic motor is connected via pinions 27 and 28.
9,30b3 connected. Screw conveyor 22
A liquid-tight damper 31 such as a rotary damper, a sliding double damper, or a rotary damper with a slide gate is connected to the rear end as a damper for discharging excavated soil, and a belt conveyor 33 is connected to the outlet 32 of this damper 31. A compressed air supply port 35 is provided at the rear end of the screw conveyor 22 to face the screw conveyor 22 and to which a compressed air supply device 34 for water shutoff is connected. Next, the operation of the above configuration will be explained.

The shield body 1 is pressed by a boosting device (not shown), and the outer and inner cutter disks 2, 13
When rotated, the excavated soil excavated by the blade 6 flows into the outer cutter disk 2 from the opening 7, is compressed by the cone plates 12 and 11 and pressurized, and then flows into the inner cutter disk 13. It is taken in through the opening 18. The soil to be excavated inside the disc 13 is scraped up by the scraping plate 15a inside the cylindrical body 15, and then transferred to the screw conveyor 22.
The liquid is introduced through the front end opening 22a, transported rearward, and discharged from the liquid-tight damper 31 onto the belt conveyor 33.
Since the inside of the rear end of the screw conveyor 22 is pressurized with compressed air, muddy water is prevented from being discharged from the liquid-tight damper 31, and the face earth pressure can be maintained constant. As is clear from the above, the first invention has the following features. 1 By appropriately selecting the digging speed of the shield body 1 and the rotational speed of the outer and inner cutter disks 2 and 13, the outer cutter disk 2 is always filled with excavated soil to generate earth pressure, and the face By creating an earth pressure balance with the mountain, it is possible to prevent the face from collapsing and inflowing.

2 Inside the outer cutter disk 2 is a cone plate 11,
12 is installed, the excavated soil taken into the disc 2 is compressed into a prone position where it easily flows in a streamlined manner, and at the same time, smooth excavation is performed without clogging and arching phenomenon. It can further contribute to creating an earth pressure balance with the ground.

Furthermore, the second invention has the following features in addition to features 1 and 2 above.

Since a scraping plate 15a and a screw conveyor 22 are installed in the rear cylindrical body 15 of the three-inner cutter disc 13, the soil to be excavated is scraped up by the scraping plate 15a and onto the screw conveyor 22. It is put in and smoothly discharged to the outside.

4 In the above embodiment, when the screw conveyor 22 was passed through the inner cutter disk 13 to carry out the excavated soil, the inside of the rear end of the screw conveyor 22 was pressurized with compressed air, so that the solid-liquid separation state was At the same time, the excavated soil can be discharged from the liquid-tight damper 31, and internal pressure within the disks 2, 13 can be generated to counter the earth face pressure, thereby contributing to prevention of face collapse.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of a shield tunneling machine according to the present invention. 1... Shield body, 2... Outer cutter disc, 11, 12... Corn plate, 13... Inner cutter disc, 15...
...Rear cylindrical body of inner cutter disc, 15a...
...Screw conveyor, 31.・・・． ...Liquidtight damper, 34...Compressed air supply device.

Claims (1)

[Scope of Claims] 1. In a shield excavator in which an outer cutter disk is rotatably mounted on the front opening of a cylindrical shield body, an inner cutter disk is rotatably provided inside the shield body behind the outer cutter disk. , a closed type shield excavator characterized in that a cone plate which extends toward the front side and extends between both of the cutter disks is installed inside. 2. In a shield excavator in which an outer cutter disk is rotatably attached to the front opening of a cylindrical shield body, an inner cutter disk is rotatably provided inside the shield body behind the outer cutter disk, and a cutter disk is provided between the two cutter disks. A cone plate that extends toward the front side is installed inside the cone plate, and a scooping plate for excavated soil is installed inside the rear cylindrical body of the inner cutter disk, and a screw conveyor is passed through the cone plate in a liquid-tight manner. A sealed shield excavator.