JP3491891B2 - Pipe underground construction apparatus and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not open and cut a collecting pipe and a drain pipe for draining water in the ground, or a buried pipe for sewage, tap water, gas, various cables, etc. Regarding how to build in the ground.

[0002]

2. Description of the Related Art Recently, a resin pipe which can be bent while avoiding an existing underground structure or the like is used by utilizing a drilling method for appropriately controlling the drilling direction (hereinafter also referred to as direction control drilling). A method of building it inside has been developed and is drawing attention.

More specifically, this method uses a directional control drilling after previously drilling a hole for passing a resin pipe into the ground.
A bendable resin tube is drawn into the forming hole. In particular, if the wall of the hole collapses when the resin pipe is retracted, it will not be possible to retract, so to avoid this,
A method of inserting a resin pipe from the other side of the hole drilling device at the stage of withdrawing the hole drilling device after the hole drilling device has been penetrated from one aboveground part or shaft to the other aboveground part or shaft Has been adopted.

[0004]

However, there is a place where the tip of the lead-in hole cannot be penetrated to the aboveground portion or the inside of the vertical shaft when constructing this kind of pipe, and the conventional method cannot cope with such a case. There was a point.

Therefore, a main object of the present invention is to enable a pipe to be built up to a predetermined portion in the ground without fear of collapse of the hole wall.

[0006]

In the present invention which has solved the above-mentioned problems, the invention according to claim 1 is a bendable outer tube which is built in the ground, and is coaxial with the tip of this outer tube. And a ring bit that is rotatably attached only in the hole rotation direction and that has a through hole along the axis, and that extends through the through hole of the outer pipe and the ring bit and extends forward of the ring bit. It is attached to the inner pipe, which is harder to bend than the pipe but is bendable, the engaging portion of the ring bit provided on the inner pipe, and the tip of the inner pipe. It is removable by rotating in the same direction and has a pressure receiving surface that is inclined with respect to the axial direction.
In addition, the taper bit having a rear surface having an engagement portion with the front surface of the ring bit, and a rotary propulsion device for rotating and propelling the inner pipe are pipe underground erection devices.

According to a second aspect of the present invention, the bendable outer tube is installed in the ground, and the outer tube is coaxially attached to the tip of the outer tube and rotatably attached only in the drilling rotation direction. A ring bit having a through hole extending along the inner pipe, an inner pipe extending through the through hole of the outer pipe and the ring bit, and extending forward of the ring bit, the inner pipe being harder to bend than the outer pipe but bendable; It is attached to the engagement part with the ring bit provided on the inner pipe, and is attached to the tip of the inner pipe, and is removable by rotating in the same direction as when drilling the inner pipe. Using a device provided with a taper bit having a pressure receiving surface inclined with respect to the rear surface and having an engaging portion with the front surface of the ring bit on the rear surface, and a rotary propulsion device for rotating and propelling the inner pipe, the rotation Turn to the inner pipe by a propulsion device Force and propulsive force are applied, the inner pipe is linearly propelled into the ground while drilling with the tapered bit at the tip of the inner pipe, and the inner pipe and the ring bit are engaged to rotate and propel the inner pipe. Is applied to the ring bit to rotate the ring bit with respect to the outer pipe to propel the ring bit and the outer pipe, and a linear propulsion force is applied to the inner pipe by the rotary propulsion device, and the taper of the tip thereof is applied. The inner pipe is curvedly propelled underground by changing the propulsion direction by the force applied to the pressure receiving surface of the bit. And at least one of the steps of propelling the outer pipe, and when the outer pipe is built in the ground for a predetermined length by performing at least one curve propulsion process, the inner pipe is opposed to the outer pipe. Retracted Te,
With the engaging portion on the rear surface of the taper bit at the tip of the inner pipe engaged with the front surface of the ring bit at the tip of the outer pipe, the inner pipe is rotated by a rotation opposite to that at the time of drilling, and It is a method of underground installation of a pipe, characterized in that the pipe is removed from the inner pipe by rotating in the same direction as when drilling.

<Operation> According to the present invention, the outer pipe can be entrained and propelled by pulling the outer pipe by the inner pipe in association with the drilling / propulsion by the inner pipe while controlling the propulsion direction. Since the work and the pipe pulling-in work can be performed at the same time, there is no fear of the collapse of the hole wall even when the outer pipe is built up to the middle of the ground.

Further, the outer pipe to be built in the ground needs to be opened for later use, and therefore the inner pipe must be recovered. On the other hand, it is desirable that the outer diameter of the tapered tip of the inner pipe is equal to or larger than the outer diameter of the outer pipe for the subsequent propelling of the outer pipe. If it cannot be removed from the inner tube, the inner tube cannot be recovered.

According to the present invention, however, even if the taper bit has a large diameter that does not pass through or is difficult to pass through the inner pipe, the taper bit at the tip of the inner pipe after the outer pipe is built in the ground for a predetermined length. Since the inner pipe can be removed from the inner pipe, it is possible to smoothly recover the inner pipe through the outer pipe, and thus it is possible to construct even if the pipe is built up to a predetermined part in the ground. Of.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. <Example of Pipe Installation Device> FIG. 1 shows a construction state of an example 1 of a pipe installation device according to the present invention. The pipe building device 1 includes a bendable outer pipe 2 to be built in the ground, a ring bit 3 coaxially attached to the tip of the outer pipe 2, an inside of the outer pipe 2 and a ring bit 3. An inner pipe 5 which passes through the through hole and extends forward of the ring bit 3 and which is harder to bend than the outer pipe 2 but is bendable; a taper bit 6 attached to the tip of the inner pipe 5; A rotary propulsion device 7 that supports the inner pipe 5 and rotates the inner pipe 5 is provided.

(Structure of Rotational Propulsion Device) The rotation propulsion device 7 is, for example, as shown in the drawing, a leader 7L tiltably supported by a base machine 7B, and a hydraulic pressure with respect to the leader 7L that can be raised and lowered in the longitudinal direction. It can be mainly configured by a rotary drive source 7M such as a hydraulic motor attached in this way. The inner tube 5 is coaxially connected to the rotation shaft of the rotary drive source 7M during propulsion, and the outer tube 2 is passed through so as to surround the outer side of the inner tube 5, but is not connected to the rotary drive source 7M and is simply a leader. It is only supported along 7L.

(Structure of Outer Tube) The outer tube 2 is formed by connecting a plurality of unit outer tubes 20 in series according to the insertion depth. As shown in FIG. 2, the unit outer tube 20 has a resin tube portion 21 that occupies substantially the entire longitudinal direction.
Is formed of a resin such as polyethylene, and a joint device 22 having a female screw portion 22a is attached to one end of the resin pipe portion and a joint device 23 having a male screw portion 23a at the other end.
Can be used. However, in the present embodiment, as the leading one, the one having the ring bit holder 26 attached to the tip as shown in FIG. 3 is used. These joint devices 22 and 23 are made of a highly rigid material such as steel. As a specific example of the resin pipe portion, for example, Hishi Pipe HPPE (high performance polyethylene) manufactured by Mitsubishi Plastics, Inc. can be preferably used.

As a mounting structure of the joint device and the resin pipe portion, for example, as shown in FIG.
At the end of the pipe mounting side, the inner pipe portion 24 having the male screw portion 24a on the outer peripheral surface and the outer diameter equal to or slightly smaller than the inner diameter of the resin pipe portion 21 and the male screw portion 24a of the inner pipe portion 24 are tightened. The outer pipe portion 2 having female screw portions 25a of opposite directions on the inner peripheral surface and having an inner diameter equal to or slightly larger than the outer diameter of the resin pipe portion.
The double structure part DB consisting of 5 is provided, and the end part 21S of the resin pipe part 21 is connected to the male screw part 24a on the outer peripheral surface of the inner pipe part 24 and the outer pipe part 2.
5 By sandwiching the inner peripheral surface with the female screw portion 25a,
It is preferable to attach the joint devices 22 and 23 to the resin pipe portion 21. In this case, on the inner surface of the end portion 21S of the resin pipe portion, the male screw portion 24 of the outer peripheral surface of the inner pipe portion of the joint device 22, 23 is formed.
A female screw portion that is screwed with a is formed, or a male screw portion that is screwed with the female screw portion 25a of the inner peripheral surface of the outer pipe portion of the joint device is formed on the outer surface of the end portion 21S of the resin pipe portion. Although it is desirable that the thread of the resin pipe portion 21 is clamped by the screw threads of the screw portions 24a and 25a when the material of the resin pipe portion 21 is somewhat softer than the male and female screw portions 24a and 25a of the joint devices 22 and 23 even if it is not formed. Since it cuts into the resin pipe portion 21 when fixing,
Can be fixed without problems.

Further, in particular, it is desirable that the joint devices 22 and 23 are formed so that the tip of the inner pipe portion 24 projects more than the tip of the outer pipe portion 25 as shown in the drawing. With this configuration,
Even if the resin pipe portion 21 is bent, its end holding portion 21
Since S does not bend at all, it is difficult for the joint device 22 and 23 to be clamped and fixed between the inner pipe portion 24 and the outer pipe portion 25.

The unit outer pipe 20 is formed, for example, by forming the outer pipe portion 25 of the joint device to be slightly larger and as a separate body, connecting the resin pipe portion 21 to the outer periphery of the inner pipe portion 24, and then forming the resin pipe portion. After sliding the outer pipe portion 25 arranged outside or in advance of the outer pipe portion 25 to position the end portion 21S of the resin pipe portion in the gap between the outer pipe portion 25 and the inner pipe portion 24, the outer pipe portion 25 is removed from the surroundings. It is compressed and fixed by sandwiching the end portion of the resin pipe portion in the gap between the outer pipe portion 25 and the inner pipe portion 24, and the thread of the female screw portion on the inner peripheral surface of the outer pipe portion is cut into or screwed into the outer surface of the resin pipe. Then, the outer pipe portion 25 can be manufactured by fixing the outer pipe portion 25 to the main body of the joint device 23 by welding W or the like.

In the present embodiment, the ring bit 3 is coaxially and abraded at the tip of the outer tube 2, that is, the tip of the most distal unit outer tube 20, via a ring bit holder 26 as shown in FIG. It can be freely attached only in the direction of rotation of the hole. The ring bit holder 26 has a tubular shape as a whole in a disassembled state as shown in FIG. 4, and has a double structure DB for sandwiching and fixing, which is similar to the joint device at the end of the unit outer tube, at the base end. Then, a ring-shaped holder clutch 27 having the same outer diameter is coaxially fixed to the tip by welding W or the like.
The inner diameter expanded portion 26 in which the inner diameter is partially expanded on the base end side of 7.
With D. On the other hand, as shown in FIGS. 8 to 10 in addition to FIG.
A ring-shaped bit clutch 32 that engages with the holder clutch 27 is fixed to the tip end of the small diameter pipe shaft portion 30 by welding or the like, and the base end portion of the small diameter pipe shaft portion 30 is formed. The outer diameter expanded portion 33 is provided in the.

In this embodiment, the outer diameter expanded portion 33 at the base end of the small diameter pipe shaft portion 30 of the ring bit 3 is attached to the bit holder 26.
The ring bit 3 is rotatably supported by the bit holder 26 by being housed in the inner diameter expanded portion 26D of
Moreover, it is connected to the bit holder 26 in the front-rear direction with a play corresponding to the step height of the clutch described later. Further, the holder clutch 27 and the bit clutch 32 are provided with the step portion 2 on one side plane as shown in FIGS. 5 and 6, respectively.
.., 32A .. have a substantially similar shape having a plurality of 7A .., 32A .. in the circumferential direction, and in the state of being attached to the bit holder 26 and the ring bit 3, respectively, as shown in FIG. Are attached so as to face each other, and when used, these step forming surfaces are brought into contact with each other as shown in FIG. And, in particular, each step portion 27A of the holder clutch 27 and the bit clutch 32.
.., 32A ... When the bit clutch 32 side is rotated in the drilling rotation direction, the step portions 3 of the bit clutch 32 mutually.
2A ... Rotates back and forth by the step height without catching on the step 27A of the holder clutch 27, and is caught when rotated in the direction opposite to the hole rotation direction, and does not rotate any more. .

On the other hand, in the ring bit 3, the outer diameter of the tip large diameter portion 31 is slightly larger than the outer diameter of the outer tube 2, and FIGS.
As shown in FIG. 10, a large number of bits 3a, 3a, ... Are provided in the circumferential direction on the front surface of the large-diameter tip portion 31, and the inner peripheral surface further extends from the base end to the middle portion in the longitudinal direction along the axial direction. Up to (not reaching the tip) groove portions 30D, 30D ... Are formed in a circumferential direction (six in the illustrated example). This groove 30
The functions of D, 30D ... Will be described later.

(Structure of Inner Tube) On the other hand, the inner tube 5 of this device example can be formed by connecting a plurality of unit inner tubes 50 in series according to the insertion depth.
As shown in FIG. 11, the unit inner tube 50 is made of a material that is harder to bend (higher in rigidity) than the outer tube 2 but can be bent, such as a steel tube, and has a female screw portion 51 at one end as a connecting means. And a male screw portion 52 formed at the other end can be used. However, as shown in FIG. 3, if the leading portion 50F of the inner pipe 5 that protrudes further forward than the ring bit is easily bent, the accuracy at the time of linear propulsion, which will be described later, becomes low. It is desirable to have higher rigidity and less bending than the above. Especially, the boundary between the leading part 50F and the base end side is just
It is preferable to locate the ring bit 3 near the front end portion because it is sufficient to prepare a unit tube exclusively for leading formed of a material having higher rigidity as the unit tube 50F of the leading portion.

By the way, if the rigidity including the outer tube 2 is shown, the following expression (1) is obtained. Inner pipe leading portion> Inner pipe proximal end side portion> Outer pipe (1) As described above, if the outer pipe 2 is not bent more easily than the inner pipe 5, smooth and steep curve propulsion becomes very difficult. ,
Also, in the inner tube 5, unless the leading portion 50F protruding from the ring bit 3 is bent more easily than the base end side portion, the straightness at the time of propulsion becomes low.

In this example, the portion of the inner pipe 5 corresponding to the ring bit 3 is formed of a substantially cylindrical bit device 55 having a structure corresponding to the engaging portion of the present invention. As shown in FIG. 3 and FIG. 12 and FIG. 13 as well as FIG. 3, the bit device 55 has an outer diameter such that it can be fitted into the inside of the ring bit 3, and a connecting means for connecting to the unit inner pipe at the tip end and the base end. As the internal thread portion 55A and the external thread portion 55B, respectively, and a plurality of ridges 55C, 55C ... Along the longitudinal direction are provided on the outer peripheral surface of the inner peripheral surface of the ring bit 3 corresponding to the grooves 30D, 30D. In the example shown, three are formed. Each convex portion 55C of the bit device 55 is inserted up to the front end limit in the corresponding ring bit groove portion 30D when the inner pipe 5 is advanced, and is not inserted any more, so that the inner pipe 5 is given a forward force. Then, the inner pipe 5 advances while pulling the ring bit 3 and the outer pipe 2 connected thereto. When the inner pipe 5 is rotated in this state, the rotational force of the inner pipe 5 is transmitted to the ring bit 3 due to the engagement of the convex streak portion 55C and the groove portion 30D in the circumferential direction. It is supposed to be rotated against. On the other hand, when the inner tube 5 is retracted with respect to the outer tube 2, the convex portion 55C of the bit device 55 is detached from the groove 30D on the inner surface of the ring bit 3, and when further retracted, the bit device 55 rings. The bit holder 26 is detached rearward and is retracted into the rear outer tube 2. In order to facilitate the insertion of the convex streak portion 55C, it is preferable that the number thereof is smaller than that of the groove portion, specifically, about half.

On the other hand, in this embodiment, a tapered bit 6 having a pressure receiving surface inclined with respect to the axial direction is detachably attached to the tip of the inner pipe 5 via a bit reducer 56 (which also constitutes the inner pipe 5). It is installed. Bit reducer 5
As shown in FIG. 14 in addition to FIG. 3, 6 has a male screw portion 56A as a connecting means at the base end portion, and is screwed and coupled to the distal female screw portion 51 of the inner pipe 5 by this male screw portion 56A. . A male screw portion 56B for connecting a tapered bit is provided at the tip of the bit reducer 56.

As the taper bit 6, for example, as shown in FIGS. 15 to 18 in addition to FIG. 3, the head of the columnar body is cut obliquely with respect to the axial direction to form an inclined surface 60. The outer diameter thereof is slightly larger than that of the ring bit 3, and a plurality of ridges 61, 61 ... Along the axial direction are circumferentially formed on the outer peripheral surface, and the bit is formed at the tip of each ridge 61. It is possible to use a device in which 62 and 62 are embedded so as to be exposed at the front end surface. Such taper bit 6
Since it has a simple structure, it can be manufactured at low cost by using casting or the like, and even if it is buried in the ground as described later, the execution cost does not significantly increase.

Particularly in this example, as shown in FIG.
The taper bit 6 has a female screw portion 6 along the axis on the base end face thereof.
3 is formed, and the taper bit 6 is attached to the tip of the inner pipe 5 by screwing the tip male thread portion 56B of the bit reducer 56 into the female thread portion 63. Further, in this example, a flow path 64 is formed that communicates with the inclined surface 60 from inside the female screw portion 63. Further, in this example, the ring bit 3 is formed on the base end surface of the taper bit 6.
A plurality of engaging protrusions 65, 65, which engage with the front bits 3a, 3a, in the circumferential direction, are provided in the circumferential direction. The engagement protrusion 65 is for removing the taper bit 6 from the tip of the inner pipe 5. Details of this removal will be described later.

<Example of Pipe Installation Method> Next, an example of a pipe installation method using the above-described apparatus example will be described. First, preferably, as shown in FIG. 19, the guide tube 100 having a length at least approximately the same as the length of the inner pipe leading portion 50F is inserted into the insertion site of the ground G. Then, although not shown, the inner pipe leading portion 50F is connected to the rotary drive shaft of the rotary propulsion device 7, and the inner pipe portion 50F is inserted by rotational propulsion or only propulsion. This propulsion is performed by lowering the rotary drive source of the rotary propulsion device 7. Further, at this time, it is desirable that the drilling stabilizing liquid such as muddy water is supplied to the tip of the inner pipe 5 and the passage 64 of the taper bit 6 to propel it.
In the present invention, the guide tube 100 may be omitted, but the propelling direction is likely to shift because the propelling is performed only by the inner tube 5 at the beginning. It is preferably used.

Next, although not shown, the unit inner tube 50 having the bit device 55 attached to the tip is attached to the ring bit 3
The tip of the bit device 55 protruding from the tip of the ring bit 3 is added to the proximal end of the inner tube leading portion 50F that has been previously propelled (see FIG. 3). Thereafter, the base end portion of the added unit inner tube 50 is connected to the rotary drive source.

Thereafter, the unit inner pipe 50 and the unit outer pipe 20 are successively added to the inner pipe 5 and the outer pipe 2, respectively, and further propelled into the ground as shown in FIG. At this time, in the present invention, the direction can be controlled during propulsion.

More specifically, when performing linear propulsion, as shown in FIG. 22, a rotary propulsion device 7 applies a rotational force and a propulsive force to the inner pipe 5, and a tapered bit 6 at the tip of the inner pipe 5 drills a hole. While propelling the inner pipe 5 straight into the ground. In this case, although the tip of the tapered bit 6 has the inclined surface 60, it moves forward while rotating around the axis, so that the influence of the pressure received by the inclined surface 60 is canceled, and it is possible to drill a hole linearly. . Further, at this time, the rotational force and the propulsive force of the inner pipe 5 are applied to the ring bit 3 by the engagement of the protrusions 55C of the bit device 55 that form the inner pipe 5 and the groove portions 30D of the ring bit (see FIG. 3). As mentioned above, the ring bit 3 is the bit holder 2
6 is rotatably supported at the tip of the outer tube 2 and each step portion 3 of the bit clutch 32 and the holder clutch 27.
2a ..., 27a ... Mutually allow the rotation of the ring bit 32 without catching when the bit clutch 32a side is rotated in the drilling rotation direction, and since the outer pipe 2 is constrained by the surrounding ground, The outer tube 2 does not rotate, but only the ring bit 3 rotates. Since the ring bit 3 is connected to the tip of the outer pipe 2 in the front-rear direction, the propulsive force applied to the ring bit 3 by the inner pipe 5 causes the outer pipe 2 to move.
Is pulled and promoted.

On the other hand, when performing curved propulsion, as shown in FIG. 23, the inner pipe 5 is rotated while the tip of the inclined surface 60 of the taper bit 6 is located on the side to be bent with respect to the rotation axis. After stopping, the propulsion force alone is applied to the inner pipe 5 by the rotary propulsion device in the same state. At this time, the force applied to the pressure receiving surface 60 of the taper bit 6 causes the taper bit 6 to move.
The propelling direction of No. 3 gradually changes, and the inner pipe 5 can be propelled into the ground in a curved manner. Further, at this time, the propulsive force of the inner pipe 5 is applied to the ring bit 3 by the engagement of the convex strip portion 55C of the bit device 55 forming the inner pipe 5 and the groove portion 30D of the ring bit inner peripheral surface. Since the ring bit 3 is connected to the tip of the outer pipe in the front-rear direction, the outer pipe 2 is curved and propelled by the propulsive force applied to the ring bit 3 by the inner pipe 5.

In the present invention, at least one of these propulsions is performed, and a desired path (a straight path or a winding path such as an S-shape may be used) to a predetermined depth. After propelling the outer tube 5, in this example, as shown in FIG. 21, the tapered bit 6 is removed from the tip of the inner tube. Specifically, as shown in FIG. 24, first, the inner pipe 5 is retracted with respect to the outer pipe 2 so that the engaging protrusions 65, 65 ... On the base end face of the taper bit 6 are set to the bits 3a, 3a on the front face of the ring bit 3. Insert in between. Then, in this state, if a rotational force in the direction opposite to that at the time of drilling (direction indicated by an arrow in the figure) is applied to the inner pipe 5, the taper bit 6 also has a rotational force in the direction opposite to that at the time of drilling. And the engaging projection 6
5, 65 is caught on the bit 3a of the ring bit, and the rotational force in the opposite direction to that at the time of drilling is also transmitted to the ring bit 3, but at that time, the step 32A of the bit clutch 32 of the ring bit 3 is The step portion 27 of the holder clutch 27 at the tip of the outer tube 2 which is restrained from rotating by the ground
As a result, the taper bit 6 cannot be rotated about the opposite direction because it is caught by A. When the inner pipe 5 is rotated in the opposite direction to that during drilling in a state where the taper bit 6 does not rotate, the taper bit 6 rotates in the drilling direction relative to the inner pipe 5. The taper bit 6 and the bit reducer 56 at the tip of the inner pipe 5 are unthreaded, and the taper bit 6 can be separated from the tip of the inner pipe 5.

If the taper bit 6 is removed,
With the taper bit 6 left in front of the outer tube 2 and the outer tube 2 being directly inserted into the ground, the inner tube 5 is pulled out from the outer tube by the rotary propulsion device 7. Thus, the outer tube 2 can be built underground. In this case, the tapered bit 6 may be buried in the ground as it is, or a vertical shaft may be dug in the vicinity of the bit removal position in advance or thereafter, and the removed tapered bit 6 may be recovered.

Although not shown in the drawings, the present invention is carried out so that it penetrates from the above-ground portion on one side or the inside of a pre-established shaft to the ground portion on the other side or the inside of a pre-arranged shaft as in the conventional example. You can also In this case, it is possible to remove the taper bit 6 from the shaft or above-ground part, or after removing it in the ground and then extruding it into the above-ground part or burying it in the ground, then pulling out the inner pipe. it can.

On the other hand, the outer pipe 2 built in the ground as described above is left in the ground G as it is, and a water collecting pipe or a drain pipe for draining the water in the ground G, or sewage or tap water. , Underground pipes for gas, various cables, etc.

<Others> (a) As the connecting means for connecting the unit outer tube 20 and the unit inner tube 50 to each other, other known connection structures can be applied other than the threaded connection as in the above example.

(B) In the present invention, not only the taper bit 6 of the above example, but also, for example, a bending shaft taper bit or an arc shaft taper bit, the peripheral surface of which is inclined with respect to the axial direction Available because it makes a face.

(C) Instead of using the bit device 55, the ridge portions 55C, 55C ... May be directly provided at predetermined positions on the outer surface of the unit inner tube 50 corresponding to the ring bit 3.

(D) If the diameter of the taper bit is formed to be equal to or larger than the outer diameter of the outer tube, the ring bit can be omitted.

(E) As means for attaching the taper bit 6 in a detachable manner, a known attachment / detachment connection structure can be adopted in addition to screw connection.

[0040]

As described above, according to the present invention, it is possible to construct a pipe up to a predetermined site in the ground without fear of collapse of the hole wall.

[Brief description of drawings]

FIG. 1 is a schematic view of a construction state of a pipe installation device.

FIG. 2 is a cutaway view of a unit outer tube.

FIG. 3 is a schematic view of a main part.

FIG. 4 is an exploded sectional view of the ring bit holder.

FIG. 5 is a front view and a side view of a holder clutch.

FIG. 6 is a side view and a front view of a bit clutch.

FIG. 7 is a side view showing an engaged state of a clutch.

FIG. 8 is a cutaway view of a ring bit and a holder portion.

FIG. 9 is a front view of a ring bit.

FIG. 10 is a vertical cross-sectional view of a main part of a ring bit.

FIG. 11 is a vertical sectional view of a unit inner tube.

FIG. 12 is a cutaway view of a bit device.

FIG. 13 is a front view of the bit device.

FIG. 14 is a cutaway view of the bit reducer.

FIG. 15 is a plan view of a tapered bit.

FIG. 16 is a side view of the tapered bit.

FIG. 17 is a vertical cross-sectional view of a main part of a tapered bit.

FIG. 18 is a rear view of the taper bit.

FIG. 19 is a construction procedure diagram.

FIG. 20 is a construction procedure diagram.

FIG. 21 is a construction procedure diagram.

FIG. 22 is an explanatory diagram of direction control.

FIG. 23 is an explanatory diagram of direction control.

FIG. 24 is a cutaway view showing a state where the taper bit is removed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Built-in device, 2 ... Outer pipe, 3 ... Ring bit, 5 ... Inner pipe, 6 ... Tapered bit, 7 ... Rotary propulsion device.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Wataru Yokoyama, 4-35, Kudankita 4-chome, Chiyoda-ku, Tokyo Inside Light Industry Co., Ltd. (56) Reference JP 10-2186 (JP, A) JP Hei 7-127384 (JP, A) JP 2000-170483 (JP, A) JP 7-243295 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 9/06 E21D 9/08

Claims (2)

(57) [Claims] 1. A bendable outer pipe built in the ground, and a through hole coaxially attached to the tip of the outer pipe and rotatably attached only in the hole rotation direction, and having a through hole along the axis. A ring bit, an inner tube that extends through the through hole of the outer tube and the ring bit, and extends forward of the ring bit, and is bendable but harder to bend than the outer tube; and the ring provided on the inner tube. A pressure receiving surface that is attached to the engaging portion with the bit and the tip of the inner pipe, is removable by rotating the inner pipe in the same direction as when drilling, and is inclined with respect to the axial direction. And a rotary propulsion device for rotating and propelling the inner pipe, and a taper bit having a rear surface having an engaging portion with the front surface of the ring bit, apparatus. 2. A bendable outer tube built in the ground, and a through hole coaxially attached to the tip of the outer tube and rotatably attached only in the drilling rotation direction, and having a through hole along the axis. A ring bit, an inner tube that extends through the through hole of the outer tube and the ring bit, and extends forward of the ring bit, and is bendable but harder to bend than the outer tube; and the ring provided on the inner tube. A pressure receiving surface that is attached to the engaging portion with the bit and the tip of the inner pipe, is removable by rotating the inner pipe in the same direction as when drilling, and is inclined with respect to the axial direction. And a rotary propulsion device for rotating and propelling the inner pipe, and a taper bit having a rear surface having an engaging portion with the front face of the ring bit. Torque and propulsion The inner pipe is linearly propelled into the ground while drilling with the tapered bit at the tip of the inner pipe, and the rotational force and the propulsive force of the inner pipe are given to the ring bit by the engagement between the inner pipe and the ring bit. Then, the linear propelling step of propelling the ring bit and the outer pipe while rotating the ring bit with respect to the outer pipe, and applying only the propulsive force to the inner pipe by the rotary propulsion device, to the pressure receiving surface of the tapered bit at its tip The force causes the inner pipe to be curvedly propelled into the ground while changing the propulsion direction, and the engagement between the inner pipe and the ring bit gives the propulsive force of the inner pipe to the ring bit to propel the ring bit and the outer pipe. If at least one of the curving propulsion steps is performed and the outer pipe is built in the ground for a predetermined length, the inner pipe is retracted with respect to the outer pipe, and With the engagement part on the rear surface of the taper bit at the tip of the pipe engaged with the front surface of the ring bit at the end of the outer pipe, the inner pipe is rotated in the opposite direction to that at the time of drilling, and the tapered bit is moved to the inner pipe. On the other hand, the method of underground installation of the pipe is characterized in that the pipe is removed from the inner pipe by rotating in the same direction as when drilling.