JPH086558B2 - Underground drilling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an underground excavation device used in a horizontal propulsion method, an arc propulsion method, and the like.

[Conventional technology]

When burying gas pipes and water pipes, a construction method is known in which a buried pipe or the like is excavated horizontally or arcuately by a non-opening method. A double tube type device is used.

This device cuts while rotating an inner pipe and an outer pipe each having an excavating blade at the tip in opposite directions.During excavation, water for earth removal is supplied to the excavated portion through the inner pipe. The waste soil slurried by the water is taken in between the inner pipe and the outer pipe, and transferred and discharged to the pipe starting side.

[Problems to be Solved by the Invention]

With this device, it is possible to efficiently discharge soil during normal cutting when both the inner pipe and the outer pipe are rotating. However, in the case of correcting the cutting direction, the rotation of the outer tube may be stopped and only the inner tube may be rotated to perform the cutting.
In such a case, there is a problem that the sediment will settle inside the outer pipe, and the discharge efficiency of the discharged soil will be extremely deteriorated. Although the soil removal efficiency can be increased by increasing the flow velocity of the drainage water, increasing the flow velocity of the drainage water is not preferable because it disturbs the ground of the excavated portion.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a device that enables efficient soil removal even during a cutting operation in a non-rotating state of the outer pipe.

[Means for solving the problem]

Therefore, in the present invention, fins are provided outside the inner tube at appropriate intervals in the longitudinal direction.

[Action]

The decrease in soil removal efficiency when the outer pipe is not rotating is due to sediment in the outer pipe settling in the outer pipe because the slurry of soil discharge is not sufficiently stirred during transfer. In the device of the present invention, the fins provided on the outer side of the rotating inner pipe agitate the sediment that has settled as described above, so that fluidization of the slurry is sufficiently ensured and efficient soil removal becomes possible.

〔Example〕

1 to 3 show an embodiment of the present invention.

The excavation device is composed of an outer pipe (1), an inner pipe (2) inserted into the outer pipe, a drive device for them, and the like.

The outer pipe (1) and the inner pipe (2) have drilling bits (3) (4a) (4b) at their tips. A spiral fin (5) is provided on the tip side of the inner pipe (2) over a predetermined length. The inner pipe (2) is supplied with earth-discharging water through the inside thereof, and has a discharge nozzle (not shown) at the tip thereof. Further, a discharge nozzle (6) is also provided near the end of the spiral fin (5).

Plate-like fins (7) are provided outside the inner tube (2) at appropriate intervals in the longitudinal direction. In this embodiment, the fins (7) are mounted at 90 mounting positions in the circumferential direction of the inner pipe.
They are provided at intervals along the longitudinal direction of the inner pipe so as to be shifted by °. The shape and installation mode of the fins (7) are not limited to those in the present embodiment, and any structure may be used as long as the desired stirring action can be obtained.

In addition, in the other drawings, (8) and (9) are drive devices for rotating and propelling the outer pipe (1) and the inner pipe (2).

The outer pipe (1) is composed of a main body (10) and a large-diameter pipe portion (11) called a pilot casing provided at the tip thereof. The outer pipe (1) has a double pipe structure up to the vicinity of its tip, and the lubricant is supplied through the space (S). Discharge ports (12 _A ) (12 _B ) for discharging the lubricant to the outside of the pipe are provided at the respective tip ends of the main body (10) and the pipe portion (11) which form the outer pipe.

According to the device as described above, the outer pipe (1) and the inner pipe (2) are propelled while being rotated in opposite directions by the respective drive devices (8) and (9) at the time of normal traveling. Waste water is supplied through the inner pipe (2) and discharged from the discharge nozzle into the excavated portion and the outer pipe. The slurried waste soil is taken in between the outer pipe (1) and the inner pipe (2), and discharged to the pipe starting side by the soil discharge water flow ejected from the spiral fin (5) and the discharge nozzle (6). It

At the time of correcting the cutting direction, the outer pipe (1) may be kept non-rotating and only the inner pipe (2) may be rotated while propelling both pipes or the inner pipe (2).

In such a case, since the stirring action due to the rotation of the outer pipe cannot be obtained, the earth and sand in the slurry tend to settle at the bottom of the outer pipe, but as shown in FIG. 4, the fins on the outer side of the inner pipe (2) ( Since 7) stirs the sediment that is about to settle, the settling is suppressed, and the slurry is sent to the starting side of the pipe in an appropriate fluidized state.

INDUSTRIAL APPLICABILITY The present invention can be applied to all types of double excavation equipment that slurries waste soil with waste water and discharges it. Therefore, the structure of the tip of the inner pipe, the supply method of the waste water, and the discharge The configuration such as the position is not limited to the above embodiment.

The device of the present invention can be applied not only to the horizontal propulsion method but also to an arc propulsion method for propelling a pipe in an arc shape.

Further, the device of the present invention employs a construction method in which the outer pipe itself is used as a buried pipe, and uses the outer pipe as a pilot pipe, connects a hole-expanding bit to the outer pipe on the side where the machining reaches, and embeds the hole-expanding bit in the rear part. It can be applied to any of the construction methods in which the pipe is pulled along with the outer pipe while being entrained.

〔The invention's effect〕

According to the apparatus of the present invention described above, even when the outer pipe is not rotating, the fins of the rotating inner pipe efficiently agitate the earth and sand which are about to settle in the outer pipe, so that the fluidity of the slurry is secured. As in the case of rotating the outer tube, the discharged soil can be discharged efficiently.

[Brief description of drawings]

1 to 3 show an embodiment of the device of the present invention. FIG. 1 is a longitudinal sectional view showing the device and excavation conditions by the device, and FIG. 2 is a partial and schematic view of an outer pipe and an inner pipe. FIG. 3 is a vertical cross-sectional view, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an explanatory view showing the stirring action of the fins. In the figure, (1) is an outer tube, (2) is an inner tube, and (7) is a fin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Ueda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. Person Hiroshi Omori 7-14-5 Chuo, Yamato City, Kanagawa Prefecture

Claims (1)

[Claims] 1. A double-pipe type excavating device comprising an outer pipe and an inner pipe, wherein the outer pipe and the inner pipe are rotated by a tip bit while rotating the outer pipe and the inner pipe. An underground excavation device characterized in that fins are provided at the bottom.