JPS602302Y2 - shield machine - Google Patents

Description

[Detailed explanation of the invention] Conventionally, in order to excavate a horizontal shaft underground, for example, Figs.
It was common to use a shield machine as shown in the figure.

The shielding machine shown in FIGS. 1 and 2 is provided with a rotary cutter C in the face chamber of a cylindrical shield tube a, and this cutter is rotated by a hydraulic motor d via a pinion e1, a reduction gear f, etc. The ground G in front of this face chamber is excavated and the excavated soil is poured into the face chamber through a liquid injection pipe passing through the rear wall b' and a liquid injection pipe h' passing through the rotation axis C' of the rotary cutter C. The mud is mixed and stirred with the viscosity imparting liquid injected through the mud to form highly viscous mud, and the earth pressure of this mud prevents the collapse of the ground G while discharging this mud to the outside by the screw conveyor 1. In such a shield machine, the viscosity-imparting liquid does not sufficiently reach the inner circumferential surface of the face chamber, so the cutting soil g in this area solidifies, and the circumferential speed of the outer circumferential portion of the rotary cutter C increases. Therefore, the rotary cutter C is subjected to a large rotational resistance, and in severe cases, there is a risk that the cutting edge C'' on the outer periphery of the rotary cutter C may be broken by the solidified excavated earth and sand g.

The object of the present invention is to provide a shield machine free from the above-mentioned dangers.

Figures 3 and 4 show an embodiment of the shield machine of the present invention. In each figure, 1 is a cylindrical shield tube made of, for example, a steel plate. A rotary cutter 3 is provided.

This rotary cutter 3 has a radial wing 7 attached to the tip of a rotating shaft 4, which has a plurality of cutting blades 5 on the front surface and a plurality of stirring blades 6 on the rear surface.
A central cutting edge 8 is attached to the tip of the blade.

9 is a hydraulic motor; 10 is a rotating shaft 11 of this hydraulic motor 9;
The pinion 12 attached to the cutter 3 is a reduction gear attached to the rear end of the rotary shaft 4 of the cutter 3, and this reduction gear meshes with the pinion 10.

13 is a bearing for the rotating shaft 4 of the cutter 3, 14 is a screw conveyor, and 15.15' is a viscosity-imparting liquid injection pipe. Both the screw conveyor 14 and the viscosity-imparting liquid injection pipe 15 are attached to the rear wall 16 of the face chamber 2. The viscosity-imparting liquid injection pipe 15' passes through the rotating shaft 4.

17 is also a viscosity-imparting liquid injection pipe, and the open end of this viscosity-imparting liquid injection pipe 17 penetrates the peripheral wall 18 of the face chamber 2.

The shielding machine of the present invention shown in FIGS. 3 and 4 uses a hydraulic motor 9 to rotate a rotary cutter 3 via a pinion 10 and a reduction gear 12, and a viscosity imparting liquid injection pipe 15.
．． When clay solution, bentonite solution, or other viscosity-imparting liquid is injected into the face chamber 2 through 15' 17, the ground G is excavated by the cutting blade 5°8 of the rotary cutter 3, and the excavated earth and sand is mixed with the above-mentioned viscosity-imparting liquid. They are mixed and stirred by the stirring blades 6 to form highly viscous mud, which effectively prevents the collapse of the ground G due to the earth pressure of this mud.

However, the mud accumulated in the face chamber 2 in this way is discharged to the outside by a screw conveyor 14.

As described above, the shielding machine of the present invention injects the viscosity imparting liquid into the face chamber of the shield tube from the peripheral wall thereof, so that the excavated earth and sand that accumulates near the inner circumferential wall of the face chamber is sufficiently mixed and stirred with this viscosity imparting liquid, making it relatively There is no risk that the mud will become highly fluid and give a large rotational resistance to the outer circumferential portion of the rotary cutter, and therefore the rotary cutter will rotate smoothly and there is no risk that the cutting edge on the outer circumference of the cutter will break. .

Further, since the structure is simple, it has the advantage of being easy to manufacture and easy to maintain.

Furthermore, in this type of earth pressure type shield machine, it is preferable to uniformly turn the excavated soil in the face chamber into mud in order to reliably press the face, but in the present invention, the viscosity imparting liquid can also be injected from the peripheral wall of the face chamber. Therefore, there is an advantage that excavated soil can be turned into mud quickly and uniformly.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of a conventional shield machine, Figure 2 is a front view of this shield machine, Figure 3 is a vertical sectional view of the shield machine of the present invention, and Figure 4 is a partial cross-section of this shield machine. FIG. 1... Shield tube, 2... Face chamber, 3
...Rotary cutter, G...Ground, 1
8... Peripheral wall of the face chamber, 17... Viscosity imparting liquid injection pipe.

Claims (1)

[Scope of utility model registration request] At the front part of the face chamber of the integrated cylindrical shield tube,
In the shield machine, a rotary cutter having a viscosity imparting liquid injection pipe is provided, and the rotary cutter is rotated while injecting the viscosity imparting liquid into the face chamber to excavate the ground in front of the face chamber. A shield machine characterized in that an open end of a viscosity imparting liquid injection pipe for injecting a viscosity imparting liquid into the face chamber is provided on the peripheral wall of the face chamber.