JPH086559B2 - Dry drilling head and dry drilling method in non-cutting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hole expanding head used in a pipe burying method by non-excavation and a hole expanding excavating method using the hole expanding head, and particularly to using water. It provides a new hole-expansion method that can be used for dry hole-excavation without using a dry method.

[Conventional technology]

As a method of burying a pipe having a relatively small diameter such as a gas pipe or a water pipe on a road or an urban area having a high traffic volume, a non-open cutting pipe burying method is known. In this construction method, after laying a pilot pipe from the starting shaft to the reaching shaft, the main pipe is sequentially buried while expanding the hole with a hole expanding head (hole expanding bit) along the pilot pipe. The hole expanding head is connected to the tip of a pilot pipe that penetrates to the reaching shaft, and performs hole expanding excavation in the process of being drawn to the starting shaft side via the pilot pipe. The hole-expanding head has a drill bit and a soil intake on a surface of the pilot pipe connection side, and is rotatably connected to a subsequent buried pipe.

As a sediment discharging method in the construction method using such a hole-expanding head, a screw rod is provided in the head main body, and the soil taken into the sediment chamber in the head from the soil discharge inlet is pilot piped using the screw rod. There is known a method of sending out in a direction. In this method, the number of revolutions of a screw rod is controlled according to the properties of the ground or the like, so that the soil in the head main body is made into a consolidated state and the soil is discharged.

In addition, as another method, it is known that water is added to the earth and sand taken into the earth and sand chamber in the head to form a slurry, and this is discharged to the buried pipe side by an earth discharge pipe using a pump or the like. .

[Problems to be Solved by the Invention]

However, in the former method among these, when the sediment taken into the head is in a solidified state or has a high viscosity, the sediment adheres to a member such as a screw rod in the head, or these members Since the flow of earth and sand is blocked by this, the screw rod does not discharge the soil smoothly from the inside of the head, and as a result, the earth pressure on the tuyere increases and it becomes impossible to efficiently propel the hole expanding head. There's a problem.

Also, in the latter method, a pump and a sediment discharge pipe must be installed in the sand chamber and shaft of the head body,
The structure of the hole expanding head etc. becomes complicated, and the connection of the drain pipe,
There is a drawback that it takes a lot of time to remove it.
Further, since the earth and sand are discharged as a water slurry, auxiliary equipment such as a separator, a water feed pump, a water tank, etc. is required, which leads to an increase in equipment cost and installation area, resulting in a high construction cost.

The present invention has been made in view of such a conventional problem, and a first object thereof is a perforated head having a simple structure and capable of efficiently discharging earth and sand taken into the head. To provide.

Further, a second object of the present application is to provide a hole expanding excavation method capable of efficiently performing excavation by using such an hole expanding head without disturbing the ground.

[Means for solving the problem]

Therefore, the hole-expanding head of the present invention has a connecting portion for the pilot pipe at the tip, at the center of the front surface of the head body having the excavating bit and the earth removal inlet on the front surface, and the rear end side communicates with the inside of the head body. A hole-expanding head that forms a cylindrical portion, and rotatably provides a screw rod for transporting soil discharge in the pilot pipe direction from the inside of the cylindrical portion to the inside of the head body. And the air can be supplied from the pilot pipe side, and the nozzle for ejecting the air is provided at the end of the screw rod in the head body, and the screw rod can be moved forward and backward in the longitudinal direction. .

Further, in the method of the present invention using such a hole expanding head, the hole expanding head is connected to a pilot pipe, and the head main body and the screw rod are rotated in opposite directions by the pilot pipe, while the hole expanding head is moved to the pilot pipe starting side. At the time of drilling for hole expansion by attracting, the air supplied through the pilot pipe is ejected from the nozzle at the end of the screw rod into the head body during the excavation, and the jet air crushes and dries the soil in the head body. After that, it is discharged to the pilot pipe side with a screw rod, and the rotation speed of the head body and the bit cut amount are adjusted to keep the soil on the front surface of the head body in a consolidated state.

[Action]

The hole expanding head of the present invention ejects high-pressure air from the nozzle at the end of the screw rod into the inside of the head body (sand chamber),
The air crushes and dries the soil in the head to make it easy to discharge, and discharges it with a screw rod. The screw rod rotates in the direction opposite to the rotation direction of the head main body by the inner pipe forming the pilot pipe, and air is supplied into the screw rod through the inner pipe, and the air is jetted from the nozzle of the rotating screw rod. At this time, air can be jetted into the entire head by advancing and retracting the screw rod in the longitudinal direction.

Sediment in the solidified state in the head and highly viscous earth and sand,
It is crushed by this high-pressure air, dried, fluidized, and easily transferred to the pilot pipe side by the rotating screw rod and discharged.

In addition, in hole drilling using such a hole expanding head,
The air ejected into the head may flow out of the soil discharge inlet and disturb the ground. Therefore, in the method of the present invention, the amount of earth and sand should be adjusted by adjusting the rotational speed of the head body and the bit depth. The soil on the front surface (cut face) of the head body is kept in a consolidated state. In other words, the sediment is taken in the range of, for example, 1/3 to 2/3 of the calculated excavation cross-sectional area, and the remaining
Excavation is performed while consolidating 2/3 to 1/3 of the earth and sand in front of the head. By doing this, it is possible to suppress the outflow of air in the head body to the outside, and to perform efficient hole drilling while appropriately avoiding problems such as disturbance of the ground due to high-pressure air supply. You can Further, since the escape of the air from the inside of the head is suppressed, the back pressure of the air effectively enhances the dischargeability of the earth and sand from the inside of the head.

〔Example〕

1 and 2 show an embodiment of the hole expanding head according to the present invention.

The hole-expanding head is composed of a head body 1 and a tube body 100 rotatably connected to the rear portion of the head body 1.
A pipe to be buried (hereinafter referred to as a buried pipe) is connected to the pipe body 100 by welding or the like.

The head body 1 has an earth removal inlet 2 and an excavation bit 3 on its front surface. That is, in the radial direction of the front surface of the head main body, there are provided a plurality of slit-shaped earth removal inlets 2 for taking in the earth and sand into the interior of the head main body 1 (sand chamber S). A plurality of drilling bits 3 are provided along it.

At the center of the front surface of the head body 1, there is provided a tubular portion 4 having a connecting portion 6 (female screw portion) for connecting to a pilot pipe at its tip and having a rear end side communicating with the inside of the head body.

A screw rod 5 for transferring soil is provided so as to be rotatable and movable in the longitudinal direction from inside the cylindrical portion 4 to inside the head body.

The screw rod 5 has a hollow inside so that air can flow therethrough, and a plurality of air jet nozzles 7a to 7c are provided at the end portion on the head body side.
Of these, the nozzle 7a is in the radial direction of the head body, the nozzle 7b is diagonally forward, the nozzle 7c is diagonally backward,
These nozzles can inject air into the entire head body. Such a screw rod 5 is connected to an inner pipe (not shown) which constitutes a pilot pipe, is rotated by the inner pipe, and is supplied with air through the inner pipe.

At the rear part of the head body 1, a tubular body 10 is provided via a rotary joint 8.
0 is rotatably connected. The rotary joint 8 is composed of a shaft body 81 fixed to the rear portion of the head main body, and a bearing 82 that pivotally supports the shaft body 81 on the side of the pipe body 100.

In the other drawings, reference numeral 9 is a lubricant, and 10 is a lubricant supply pipe.

Next, the hole expanding method of the present invention using such a hole expanding head will be described.

As shown in FIG. 3, the hole-expanding head (a) has a starting shaft X.
It is attached to the tip of the pilot pipe (C) which penetrates from the arrival shaft to the reaching shaft Y, and the hole is excavated while being pulled toward the starting shaft X. That is, the hole expanding head (a) is pulled by the pilot pipe (c) that is rotated by the driving force of the drive device (d) and retracts in the starting vertical shaft X direction while only the head body 1 is being rotated and is pulled. The ground is drilled by bit 3 Then, the pipe body 100 carries the embedded pipe (b) at the rear part thereof, and in a non-rotating state, the head body 1
Follow. Buried pipe (b) guided to the expansion head (a)
Is added on the reaching shaft Y side as the hole expanding head advances, and the burial is completed when the hole expanding head reaches the starting shaft X side. In such a pipe burying process, the rear end of the buried pipe (b) is usually pressed by the pipe pushing jack (e) on the reaching shaft Y side to supplement the propulsive force of the buried pipe (b).

Sediment generated by excavation is taken into the inside of the head body 1 (sand chamber) from the earth discharge inlet 2, and is further discharged in the pilot pipe direction by the screw of the screw rod 5 rotating in the direction opposite to the rotating direction of the head body. Be transferred.

Air is supplied to the screw rod 5 through the inner pipe of the pilot pipe (c), and this air is jetted into the head main body from the nozzles 7a to 7c at the end of the rotating screw rod, and is in a solid state in the head main body. Crush earth and sand and highly viscous earth and sand,
Dry and fluidize for easy discharge. At this time, by moving the screw rod 5 back and forth in the longitudinal direction, the air from the nozzles 7a to 7c can be spread throughout the head main body. Further, since the screw rod 5 rotates in the direction opposite to the head main body, the crushing effect by the air is further enhanced.

In such a hole drilling, according to the method of the present invention, the amount of earth and sand taken into the head body 1 is limited by adjusting the number of revolutions of the head body and the bit cutting amount thereof, and as shown in FIG. 1 Excavate while consolidating the soil in the front. That is, in the method of the present invention in which high-pressure air is ejected into the head body 1, air may flow from the earth removal inlet to the excavation portion and disturb the ground. On the other hand, as described above, by consolidating the head front surface by limiting the amount of sediment taken in, air is prevented from flowing out, and excavation can be performed while stably holding the ground. In addition, since the air does not escape from the inside of the head, the back pressure of the air enhances the dischargeability of the soil from the inside of the head, which enables efficient soil discharge.

 The excavation amount of the hole expansion head is calculated by the following formula.

Q = π (D−d) N · t where D: outer diameter of expanded head d: outer diameter of pilot pipe N: rotational speed of head body t: bit depth of cut In the present invention, the amount of earth and sand taken in is usually Q. The rotation number of the head and the bit cut amount are controlled so that the amount is limited to about / 3 to 2Q / 3, and a soil compaction state is formed on the front surface of the head.

FIG. 5 is a schematic view of the entire excavating device. In the figure, 11 is an air pump, 12 is a separator for separating air and soil, and 13
Is an earth discharge flow meter, and this earth discharge flow meter 13 controls the amount of earth and sand taken in.

〔The invention's effect〕

The hole expanding head of the present invention described above has an extremely simple structure, and furthermore, high-pressure air is ejected from the nozzle of the rotating screw rod end into the inside of the head main body to crush and dry the soil in the head. Therefore, the sand can be discharged smoothly and efficiently by the screw rod.

Further, according to the method of the present invention using such a hole-expanding head, the amount of earth and sand taken into the head is limited by adjusting the number of rotations of the head body and the bit cut amount, and the earth and sand on the front surface of the head body is removed. Since it is kept in a consolidated state, it is possible to suppress the outflow of air in the head body to the outside, and avoid problems such as disturbance of the ground due to high-pressure air supply properly, while performing efficient dry hole drilling. It can be carried out. Further, since the escape of air from the inside of the hole-expanding head is suppressed, the back pressure of the air can efficiently enhance the dischargeability of the earth and sand from inside the head. Furthermore, the method of the present invention only needs to use a hole-expanding head having a simple structure, and furthermore, there is no need for auxiliary equipment such as a water pump and a separator, which are required in the conventional water slurry discharging method, Therefore, the installation area of the equipment is extremely small, and the equipment cost can be significantly reduced compared to the above method.

[Brief description of drawings]

1 and 2 show an embodiment of the hole expanding head according to the present invention. FIG. 1 is a longitudinal sectional view and FIG. 2 is in FIG.
It is sectional drawing which follows the II-II line. FIG. 3 is an explanatory view showing the hole expanding method of the present invention. FIG. 4 is an explanatory view showing a consolidated state of the front surface of the hole expanding head. FIG. 5 is a schematic view of an excavator used for carrying out the present invention. In the figure, 1 is a head main body, 2 is an earth removal inlet, 3 is an excavation bit, 4 is a cylindrical portion, 5 is a screw rod, 7a to 7c are nozzles, (a) is a hole expanding head, and (b) is buried. Pipe, (c) is pilot pipe.

Claims (2)

[Claims] 1. A cylindrical portion having a connecting portion with a pilot pipe at its tip and a rear end side communicating with the inside of the head body, is formed at the center of the front surface of the head body having an excavation bit and a soil intake port on the front surface. A head for expanding holes, in which the screw rod for transferring the discharged soil in the direction of the pilot pipe is rotatably provided from the inside of the tubular portion to the inside of the head body, and the inside of the screw rod is made hollow to form the pilot pipe side. Air is supplied from the head body, the nozzle for ejecting the air is provided at the end of the screw rod in the head body, and the screw rod is configured to be movable back and forth in the longitudinal direction. Hole head. 2. The expansion head according to claim 1 is connected to a pilot pipe, and the expansion pipe is expanded by pulling the expansion head toward the starting side of the pilot pipe while rotating the head body and the screw rod in opposite directions by the pilot pipe. When drilling holes,
During excavation, the air supplied through the pilot pipe is jetted from the nozzle at the end of the screw rod into the head body, and the jet air crushes and dries the earth and sand in the head body, and then the pilot rod side is pushed by the screw rod. A dry hole expanding method in a non-excavation method, characterized in that the soil on the front surface of the head body is kept in a consolidated state by discharging and adjusting the number of revolutions of the head body and the bit cut amount.