JPH0774581B2 - Underground drilling equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an underground excavation device used in a horizontal propulsion method, a circular arc propulsion method, and the like, and more particularly to an excavation device suitable for excavating rock or gravel layers.

[Conventional technology]

When burying a gas pipe, a water pipe, etc., a construction method is known in which a buried pipe or the like is excavated in a horizontal or arc shape by a non-open cutting method.

In this construction method, the longer the cutting distance is, the more easily an error occurs in the cutting direction. Therefore, it is necessary to frequently correct the hole bending during the cutting.

By the way, as an excavation device for applying such a construction method to the ground such as rock or gravel layer, it is composed of an outer pipe and an inner pipe, equipped with a percussion drill at the tip of the inner pipe, and for correcting hole bending, There is known a structure in which the tube hole portion on the tip side of the tube is eccentrically inclined with respect to the outer tube axis.

In such an excavator, during normal excavation, the outer pipe is rotated and the ground is excavated by a percussion drill at the tip of the inner pipe. When correcting the hole bend, the inner pipe is moved forward with respect to the outer pipe, and the eccentric pipe hole at the tip of the outer pipe advances the drill at the tip of the inner pipe in the direction to be corrected, and then the outer pipe is drilled. Is driven along the inner pipe.

[Problems to be Solved by the Invention] However, even if the inner pipe is used to dig the inner pipe to correct the hole bend, if the outer pipe having high rigidity is propelled along the inner pipe,
Due to the rigidity of the outer pipe, the soil wall on the tip side of the inner pipe collapses and the inner pipe is returned to its original state, and there is a problem that a sufficient correction function cannot be achieved.

In this way, the conventional device cannot obtain a sufficient bending action,
In particular, it can be said that there is almost no device that can perform efficient bending correction on a pipe having an outer diameter of 250 mm, which has high rigidity.

The present invention has been made in view of such conventional problems,
It is an object of the present invention to provide an apparatus capable of appropriately correcting the receding direction even for a pipe having a relatively large diameter.

[Means for Solving the Problems]

Therefore, the present invention comprises an outer tube, an inner tube having a percussion drill at the tip, and a drive device for rotating the outer tube on the tube starting side and propelling the inner tube and the outer tube. The basic feature is that the outer surface of the tube is provided with an inclined surface inclined toward the tip of the outer tube in the axial direction of the outer tube.

[Action]

In such a device, at the time of normal cutting, the outer pipe and the inner pipe are simultaneously propelled while rotating the outer pipe and operating the percussion drill protruding from the tip of the outer pipe.

A fluid such as water is supplied to the excavation portion through an inner pipe or the like, and soil discharged by excavation is taken in between the inner pipe and the outer pipe and discharged to the pipe starting side.

When the direction is corrected, the position of the outer tube is adjusted in the circumferential direction so that the inclined surface of the outer surface of the distal end faces the direction opposite to the correction direction. Then, from this state, while operating the percussion drill at the tip of the inner pipe, the outer pipe is made non-rotating and both pipes are simultaneously propelled. As a result, the inclined surface of the outer surface of the outer tube receives the reaction force of the soil wall, and the orientation of the outer tube is corrected in the direction opposite to the side where the inclined surface is formed.

As described above, as in the case of the direction correction in the conventional double pipe type excavator, in the method of first advancing the inner pipe in the correction direction and then advancing the outer pipe along the inner pipe, Due to the rigidity, most of the pushing force is received by the tip of the inner pipe protruding from the outer pipe, the force intensively acts on the soil wall and the ground collapses, causing the inner pipe to move in the original direction (before correction). Direction). On the other hand, in the present invention, since the outer tube itself is bent by the inclined surface of the outer tube tip, the entire outer tube receives the pushing force,
Since the pressure receiving area is wide, the pushing force does not concentrate and the collapse of the earth wall is prevented.

Further, since the outer pipe is not simply pushed into the soil wall but is pushed into the excavation hole previously dug by the inner pipe, a large amount of pushing can be secured.

In the case of the circular arc propulsion method, the above-mentioned direction correcting function is also used for gradually correcting the direction of the pipe into an arc shape.

〔Example〕

1 to 3 show an embodiment of the device of the present invention.

The device of the present invention comprises an outer tube 1, an inner tube 2 inserted into the outer tube 1, and a drive device 5 provided on the tube starting side.

The outer tube 1 has an inclined surface 3 on the outer surface on the tip side (range L in the figure). The inclined surface 3 is inclined in the outer tube axial direction toward the outer tube tip. The angle of the inclined surface 3 with respect to the outer tube axis is usually set to a size of about several degrees. It should be noted that this inclined surface 3 does not necessarily have to be a flat surface, and the whole or part of the longitudinal direction may be curved.

Bits 4 are provided at a plurality of locations in the circumferential direction of the outer tube tip.

The inner tube 2 has a percussion drill 6 made of a so-called air hammer or the like at the tip thereof. The percussion drill 6 has a plurality of hammers 7 for striking, and rocks and gravel are crushed by moving these hammers 7 forward and backward at high speed. A bit 9 is provided on the front surface of each hammer 7. Further, compressed air for driving is supplied to the drill through an air hose 8 which is passed through the inner tube 2.

Furthermore, a plurality of discharge nozzles 10 are provided at the tip of the inner pipe,
The muddy water for soil discharge supplied through the inner pipe 2 can be supplied to the excavation part.

The drive device 5 has a drive mechanism for rotating the outer pipe 1 and propelling the inner pipe 2 and the outer pipe 1.

An example of the specific structure of the above configuration is as follows.

・ Outer pipe outer diameter: 200-300mm ・ Inclined surface Inclination: around 7 ° Length: around 500mm In the above equipment, the percussion drill 6 at the tip of the inner tube 2 is cut while protruding from the tip of the outer tube 1. Proceed. In the case of performing ordinary cutting (straightening), the outer pipe 1 is rotated and the percussion drill 6 is operated to simultaneously propel the outer pipe and the inner pipe as shown in FIG.
Muddy water is jetted from the discharge nozzle 10 to the excavation part, and the slurry soil is taken in through the gap S between the inner pipe 2 and the outer pipe 1,
It is discharged to the starting side of the pipe.

When the cutting direction is detected by a gyro or the like at an arbitrary stage during excavation and an error exceeding the allowable range is generated in the direction, the direction is corrected at that stage.

5 (A) and 5 (B) show a method of correcting the direction,
After the cutting is stopped in the state shown in FIG. 5 (A), the direction to be corrected and the correction amount are detected by a gyro or the like, and the outer tube 1
The inclined surface 3 of the is oriented in the direction opposite to the direction to be corrected in the radial direction of the outer tube. Then, in this state, the percussion drill 6 at the tip of the inner pipe 2 is operated to make the outer pipe 1 non-rotating and to propel both pipes at the same time. By this promotion, Fig. 5 (B)
As shown in FIG. 3, the inclined surface 3 of the outer tube receives the reaction force of the soil wall, and the outer tube 1 and the inner tube 2 are corrected in the direction opposite to the inclined surface 3.

As described above, in the device of the present invention, since the direction correction is performed by bending the outer pipe itself, the pushing force at the time of correction is received by the entire outer pipe, and thus the collapse of the earth wall during the pushing is prevented. . Bend the inner tube like a conventional device,
If the outer pipe is made to follow it, almost all of the pushing force at the time of correction will be received by the tip of the inner pipe protruding from the outer pipe. Causes the collapse of the soil wall, and the inner pipe is returned to the original direction (direction before correction).

The device of the present invention can perform not only the vertical direction correction but also the direction correction in any direction by orienting the inclined surface 3 180 ° opposite to the direction to be corrected.

The device of the present invention can be applied not only to the horizontal propulsion method but also to the arc propulsion method of propelling the pipe in an arc shape. In this case, the straight excavation and the direction correction function are used to move upward. The pipe is propelled in an arc shape by alternately repeating the excavation for correcting the direction.

Further, the device of the present invention is a construction method in which the outer pipe itself is a buried pipe,
And a method of using the outer pipe as a pilot pipe, connecting a hole-expanding bit to the outer pipe on the side of reaching the progress, and entraining the hole-expanding bit to the start side by the outer pipe while entraining the buried pipe in the rear part. Can also be applied to.

〔The invention's effect〕

According to the present invention described above, the following effects can be obtained.

It is possible to correct the cutting direction reliably and efficiently,
A large bending correction effect that cannot be obtained by the conventional device can be obtained.

Due to its excellent bending correction function, it is possible to perform appropriate bending correction even for a pipe whose outer diameter exceeds 250 mm.

At the time of correcting the direction, the pipe is not simply pushed into the soil wall, but the outer pipe is pushed into the digging hole formed by the inner pipe.

Since the soil removal is sufficiently taken in even during the direction correction cutting, a large pushing amount can be obtained, and efficient bending correction can be performed also from this aspect.

There is no need to change tools when correcting the direction,
The structure is simple, there are few failures, and ordinary excavation itself can be performed efficiently.

INDUSTRIAL APPLICABILITY As described above, the present invention is capable of performing reliable and efficient direction correction irrespective of the cutting distance, pipe diameter, etc., and is particularly useful as an underground excavation device for rocks and buried pipes for gravel layers It is a thing.

[Brief description of drawings]

1 to 3 show one embodiment of the device of the present invention. FIG. 1 is a longitudinal sectional view, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. FIG. FIG. 4 is an explanatory view showing a normal excavation condition by the device of the present invention. FIGS. 5 (A) and 5 (B) are explanatory views showing stepwise the case where the direction correction is performed by the device of the present invention. In the figure, 1 is an outer pipe, 2 is an inner pipe, 3 is an inclined surface, 5 is a driving device, and 6 is a percussion drill.

 ─────────────────────────────────────────────────── ─── 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 tube on the tip side of an outer tube, comprising an outer tube, an inner tube having a percussion drill at its tip, and a drive device for rotating the outer tube on the tube starting side and propelling the inner tube and the outer tube. An underground excavation device having an outer surface provided with an inclined surface inclined in the outer pipe axial direction toward the outer pipe tip.