JP2005009103A - Double pipe drilling method of lock bolt and its drilling double pipe construction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double pipe drilling method of a lock bolt and its drilling double pipe construction capable of making a boring diameter smaller without accompanying any inconvenience in terms of strength and smoothly and easily ensuring the circulation of a fluid and the removal of excavated slime. <P>SOLUTION: The solid lock bolt 14 having a lost bit 12 on the front end is used as a drilling rod, and the lock bolt and a hole retaining pipe 16 separately surrounding almost the overall length of the lock bolt are used for both the inner and the outer of the drilling double pipe. The lock bolt 14 is connected to a fluid swivel 28 through an adaptor having a passing-through channel in the direction of the axis to enable the fluid to circulate into the hole retaining pipe 16, the fluid is supplied into the hole retaining pipe 16 from the fluid swivel, and the removal of the excavated slime along the circumferential surface of the hole retaining pipe can be ensured by discharging the fluid to the outside from the front end of the hole retaining pipe. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of drilling a lock bolt with a boring machine having a rotating function and a striking function using a drilled double pipe as a combination of an inner and an outer, and a structure of the drilled double pipe About.
[0002]
[Prior art]
As a construction method of the lock bolt in the soft ground or the like that can be predicted that the hole wall after drilling is difficult to stand by itself, for example, a hole holding pipe (also referred to as a casing pipe) is arranged on the outer periphery of the self-drilled lock bolt. A so-called double pipe drilling is known.
[0003]
As a known example of the double pipe drilling of this lock bolt, for example, a configuration disclosed in Japanese Patent Application Laid-Open No. 2002-129899 is known.
[0004]
In this known drilling method, a conventional hollow self-drilling lock bolt is used as a so-called drilling rod for excavation. Then, the bit attached to the tip of the self-drilling lock bolt is rotated or hit by the self-drilled lock bolt, and excavation is performed, and the hole-holding pipe is caused to follow the progress to synchronize. Double pipe drilling in this known configuration is performed.
[0005]
[Problems to be solved by the invention]
By the way, when a rotational force and a striking force are applied to such a hollow self-drilling lock bolt, the hollow self-drilled lock bolt itself is required to have rigidity enough to withstand it. And in such rigidity reinforcement | strengthening, the thickening is usually taken.
[0006]
However, since the increase in the thickness of the self-drilling lock bolt is to increase the diameter of the lock bolt, it is inevitable that the diameter of the hole-holding tube around it is increased. It has become. That is, in this known double-pipe drilling, it is inevitable that the diameter of the drilled hole itself is increased.
[0007]
By the way, when drilling this type of drilling hole, the drilling hole diameter is proportional to the drilling time, and if the drilling hole diameter is small, the drilling time is shortened even if the drilling hole has the same depth. Will be.
[0008]
That is, it is considered that the double pipe drilling by the known self-drilling lock bolt naturally delayed the excavation time.
[0009]
Here, in the case of double pipe drilling, it is required to discharge drilling slime at the bottom of the hole, and if it is a hollow self-drilling lock bolt, fluid such as air, water, etc. can be fed through this hollow part. Become. In other words, when the drilling rod is changed from a self-drilling lock bolt to another type of member, it is necessary to consider the feeding of the fluid and the discharge of the drilling slime, so that simple replacement of the member cannot be easily performed. .
[0010]
The present invention aims to reduce the diameter of the drilling hole without incurring any problems in strength, and also enables double-pipe cutting of a lock bolt that can ensure smooth and easy fluid flow and drilling slime discharge. An object is to provide a hole method and a drilled double pipe structure.
[0011]
[Means for Solving the Problems]
In order to achieve this object, according to the double tube drilling method for a lock bolt according to claim 1 of the present invention, a solid lock bolt having a lost bit at its tip is rotated by a boring machine, and It is used as a drilling rod driven by striking.
[0012]
In other words, the double-pipe drilling method for a lock bolt according to the present invention comprises a solid lock bolt having a lost bit at the tip, and a hole-holding tube that surrounds and surrounds substantially the entire length of the lock bolt. This is a double pipe drilling hole used as an inner and outer. Then, a hollow rotating body of a fluid swivel is fixedly screwed to a drive shaft of a drifter that can move forward and backward, which is a rotation / blow driving device of a boring machine, and the axial direction of the hollow rotating body is fixed to the hollow rotating body. A lock bolt is fixedly screwed through an adapter having a through-flow path, so that the lock bolt functions as a drilling rod to which a driving force is applied from the rotary drive shaft and can be sealed. The fluid from the fluid swivel is connected to the outer connection port of the fluid swivel through a hole retaining pipe coupler having a bore, and is inserted into the hole retaining hole synchronously with the progress of the drilling of the lock bolt. The pipe is fed from the flow path of the adapter, and this fluid is discharged from the end of the hole holding pipe to the outside. Double pipe drilling method of the lock bolt is embodied.
[0013]
According to claim 2 of the present invention, after excavation to a predetermined depth, the hole-holding pipe and the lock bolt in the hole are respectively removed from the fluid swivel together with the hole-holding pipe coupler and adapter connected thereto. In addition, by directly connecting the retaining tube in the drilling hole to the hollow rotating body after removing the adapter, the grout material is injected into the drilling hole through the retaining tube. It has become.
[0014]
Furthermore, in claim 3 of the present invention, in parallel with the injection of the grout material, the retaining tube is pulled up and separated sequentially.
[0015]
Further, in the drilled double tube structure of the present invention, a fluid swivel having a hollow rotating body connected to a drive shaft of a drifter capable of advancing and retreating which is a rotation / blow drive device of a boring machine, and the fluid swivel It is fixedly connected to the hollow rotating body under the screwing, and has an axial through-flow passage that communicates with the hollow rotating body around the female screw recess to which the lock bolt is screwed. An adapter that functions as a joint member between the hollow rotating body and the lock bolt, a connection end that is connected to the outer connection port of the fluid swivel under the fitting, and a male thread portion formed at the rear end of the hole-holding tube A cover body that has screwable female thread portions at the hollow rear end and the hollow front end of the tubular body, respectively, and that partially defines and opens the formed opening window on its peripheral surface. Tubular book Provided on the movable, fluid swivel around the lock bolt, and a Hoanakan coupler having a function as a joint between Juana tube are mounted against.
[0016]
Then, the solid lock bolt is connected to the rotation drive shaft of the boring machine drifter so as to be integrally rotatable through the hollow rotary body of the fluid swivel and the adapter, so that the lock bolt functions as a drilling rod. At the same time, the fluid sent from the fluid swivel to the inside of the hole holding pipe through the adapter through-flow channel is discharged to the outside from the hole holding pipe tip, thereby ensuring that the drilling slime is turned back along the outer circumference of the hole holding pipe. In addition, the drilled double pipe structure of the present invention is constructed.
[0017]
Further, in claim 5 of the present invention, the hole-holding pipe coupler is disposed around the inner pipe so as to be slidable in the axial direction with respect to the inner pipe as the tubular main body and the inner pipe. It is embodied as a double pipe structure in combination with an outer pipe as a cover body. Then, by inserting a tool through an opening window formed in the inner pipe, the lock bolt can be disconnected in the hole-holding pipe coupler, or the lock bolt can be gripped at the time of connection. The hole tube coupler is embodied.
[0018]
Furthermore, in claim 6 of the present invention, the male threaded portion of the hole-holding tube is embodied as being formed so as to be directly screwable with the female threaded portion of the hollow rotating body of the fluid swivel.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
As shown in FIGS. 1 and 2, in the drilled double pipe structure 10 according to the present invention, a solid lock bolt (also referred to as a deformed reinforcing bar) 14 having a lost bit 12 at the tip, A hole-holding pipe (also referred to as a casing pipe) 16 that surrounds and surrounds the entire length is used as an inner and an outer of the drilled double pipe 18, respectively.
[0021]
As shown in FIG. 1, in the present invention, this drilling is carried out as a double pipe drilling by a boring machine 20 having a rotation function and a striking function using the lock bolt 14 as a drilling rod. A double tube 18 is embodied.
[0022]
An outline of the boring machine 20 will be described below.
[0023]
As this boring machine 20, for example, a top hammer type inverter chisel provided with a drifter (rotation / hitting drive device) 22 having a rotation function and a striking function can be exemplified. In this inverter chisel, the drifter is a guide rail. 24 can be moved forward and backward.
[0024]
Since this type of boring machine (inverter chisel) 20 is well known and its configuration itself is not the gist of the present invention, a detailed description of this boring machine is omitted here.
[0025]
As can be seen from FIG. 2 with reference to FIG. 1, in the drilled double pipe structure 10 of the present invention, a fluid swivel that allows fluid such as air and water to flow through the drive shaft 26 of the drifter 22. 28 hollow rotating bodies 30 are fixedly connected so as to be integrally rotatable, for example, by screwing at the rear end thereof. As shown in FIG. 3, in the present invention, the lock bolt 14 serving as the inner is fixedly connected and connected to the hollow rotating body 30 of the swivel via an adapter 32 so as to be integrally rotatable.
[0026]
As shown in FIG. 4 in addition to FIG. 3, this adapter 32 is provided in the hollow rotary body 30 of the fluid swivel and has a hollow male screw portion 36 that can be screwed into the screw portion 34 at its rear end. By having a bottomed female screw recess 38 into which the lock bolt 14 is screwed at the front end thereof, it is formed so as to function as a joint member between the hollow rotating body of the fluid swivel and the lock bolt. The adapter 32 has, for example, a plurality of circulation holes 40 communicating with the hollow portion 36a of the external thread portion 36 around the bottomed female screw recess at the front end, so that the fluid from the fluid swivel 28 is supplied to the circulation hole. It can be released around the lock bolt.
[0027]
That is, the adapter 32 is formed as a substantially hollow body having a through flow path in which the hollow portion 36 a and the flow hole 40 are combined.
[0028]
Thus, in the present invention, the solid lock bolt 14 having the lost bit 12 at the tip can be integrally rotated with respect to the drive shaft 26 of the drifter 22 via the adapter and the rotating hollow body 30 of the fluid swivel. Therefore, the rotational drive of the drive shaft and the striking drive are transmitted to the lock bolt and eventually the lost bit 12 at the tip thereof. Therefore, the lock bolt 14 can be used as a drilling rod in the drilled double pipe 18.
[0029]
As this lost bit 12, since a well-known commercially available excavation bit can be used, detailed description of this lost bit is omitted here.
[0030]
In addition, the hole holding pipe 16 that surrounds and surrounds the lock bolt is connected to the outer connection port 44 of the fluid swivel 28 via the hole holding pipe coupler 42 (see FIGS. 1 and 3).
[0031]
As can be seen from FIGS. 2 and 3, the hole-holding pipe coupler 42 in the present invention is formed to have a tubular body 46. In this embodiment, the hole-holding pipe coupler 42 is configured as a double pipe structure having the tubular main body 46 as an inner pipe.
[0032]
The hole-holding pipe coupler 42 is formed on the hole-holding pipe 16 with a connection end 48 connected to the outer connection port 44 of the fluid swivel at the rear end of the inner pipe serving as the tubular body 46. By defining the female thread portion 50 that can be screwed into the male thread portion 16a at the tip thereof, it is configured to function as a joint between the fluid swivel 28 and the retaining tube around the lock bolt.
[0033]
In the present invention, a predetermined opening window 52 is partially defined and formed on the peripheral surface of the inner tube (tubular body) 46.
[0034]
The opening window 52 is a work window for inserting a work tool such as a spanner that holds the lock bolt 14 or the adapter 32 positioned inside the inner pipe 46, and is provided with this opening window. Accordingly, for example, the lock bolt and the adapter can be easily disconnected or connected within the hole-holding pipe coupler 42.
[0035]
For example, the opening angle of the opening window 52 is set to approximately 180 °.
[0036]
By the way, the hole-holding pipe coupler 42 is required to have a function capable of ensuring a fluid-free flow from the fluid swivel 28. Therefore, in this embodiment, the opening window 52 can be sealed by the outer tube 54 arranged around the inner tube.
[0037]
The outer tube 54 is arranged around the inner tube 46 so as to be slidable in the axial direction, and the sealing and opening of the opening window 52 can be switched by the forward and backward sliding in the axial direction. (See FIGS. 2A and 2B).
[0038]
For example, when the outer tube 54 slides in the distal direction (leftward in the drawing) shown in FIG. 2A, the opening window 52 of the inner tube is sealed by the outer tube. Then, by sliding the outer tube 54 in the rear end direction (rightward in the figure) of the inner tube 46, the opening window 52 is opened as shown in FIG.
[0039]
Here, in the hole-holding pipe coupler 42, it is required to seal the opening window 52 of the inner pipe when the outer pipe 54 is disposed at the tip position (sealing position). This is because it is necessary to prevent leakage of the fluid from the opening window 52 when the fluid is fed from the fluid swivel 28. Normally, the fluid is applied between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube. The degree of sealing is sufficiently maintained by the lubricated lubricant or the like. However, if necessary, a sealing member 58 such as an O-ring is provided in the circumferential groove 56 of the inner tube to ensure the sealing reliability. It is good also as a structure which raises more.
[0040]
For example, by attaching a snap ring 62 or the like to the circumferential groove 60 of the inner tube 46, excessive sliding of the outer tube 54 with respect to the inner tube, particularly a reliable stop of the outer tube in a sealed position can be achieved. It can be done without complications.
[0041]
By the way, as shown in FIGS. 2 and 3, the fluid swivel 28 usually has a connection port 64 protruding in the radial direction thereof. It may happen that the outer tube 54 slides in the rear end direction, that is, the outer tube is prevented from being pulled up. Therefore, as shown in FIG. 2B and FIG. 3, in this embodiment, notches 66 for avoiding contact with the connection port 64 are provided at the rear end of the outer tube, for example, at a plurality of locations. Provided.
[0042]
According to such a configuration, by aligning the notch 66 with the connection port 64, the outer tube 54 can be easily pulled up without being engaged.
[0043]
In this embodiment, the notch 66 is provided so as to be inclined with respect to the axis of the outer tube 54 or the like. According to such a configuration, the outer tube 54 can be slid while being twisted with respect to the inner tube 46, so that the workability is sufficiently improved and an O-ring or the like is provided. Further, damage to the O-ring and the like can be reliably prevented.
[0044]
A double pipe drilling method using the drilled double pipe 18 having the drilled double pipe structure 10 as described above will be described below.
[0045]
In addition, the lock bolt 14 and the hole retaining pipe 16 that form the hole-drilling double pipe 18 are both made to correspond to the hole-drilling depth by connecting single pieces of about 1.0 to 1.5 m. Normally, the hole-holding tube is joined under direct screwing, whereas the lock bolt is joined via a bolt coupler 68 (see FIG. 1).
[0046]
As shown in FIG. 1, in the double pipe drilling method of the present invention, a lock bolt 14 having a lost bit 12 at its tip is used as a drilling rod that is driven to rotate or hit by a drifter 22 of a boring machine. Then, according to the drilling depth, the lock bolt and the retaining tube 16 are sequentially added.
[0047]
Here, when the rock bolt 14 is excavated, slime generated by excavation (drilling slime) stays in the bottom of the hole. In this double pipe drilling method, the fluid supply connected to the connection port 64 of the fluid swivel is provided. A fluid from a source (not shown) is sent from the fluid swivel 28 to the inside of the hole holding pipe 16 and discharged from the tip of the hole holding pipe to the outside, thereby drilling slime along the outer peripheral surface of the hole holding pipe. Can be secured.
[0048]
That is, the drilling slime staying at the hole bottom is pushed back toward the hole along the outer peripheral surface of the hole holding pipe by the fluid discharged from the tip of the hole holding pipe 16, and is thus discharged from the hole outside the hole. Therefore, the staying of the drilling slime in the drilling hole is surely prevented.
[0049]
Note that when the solid lock bolt 14 is used as a drilling rod, the fluid is fed into the hole-holding tube 16 between the lock bolt and the hollow swivel 30 of the fluid swivel. This is made possible by the presence of the adapter 32 having
[0050]
Further, by providing an opening window 52 that can be sealed in the hole holding pipe coupler 42, the lock bolt 14 is disconnected and connected in the hole holding pipe coupler, or in the hole holding pipe without leakage from the opening window. Both fluid distributions can be easily ensured.
[0051]
Then, by repeating such excavation by the lock bolt 14 and addition of the lock bolt and the hole retaining pipe 16, excavation of the hole 70 to the planned depth can be achieved.
[0052]
After completion of the excavation of the hole 70, grouting is performed on the hole.
[0053]
The grouting with respect to the hole 70 is performed as injection of the grouting material into the hole, and in the double tube drilling method of the present invention, the grouting material is injected using the hole retaining tube 16. .
[0054]
After excavation of the hole 70 by the lock bolt 14, the hole retaining pipe 16 and the lock bolt of the hole-drilling double pipe 18 used for the excavation are both fluid swivel 28 together with the adapter 32 and the hole retaining pipe coupler 42. Removed from. The retaining tube 16 is directly connected to the fluid swivel 28 by directly screwing the retaining thread 16a of the retaining tube into the female threaded portion 34 of the hollow rotating body from which the adapter 32 has been removed. Under this connection, the grout material is injected from the fluid swivel through the hole holding tube into the hole 70 (see FIG. 3).
[0055]
When the grout material is injected through the hole-holding tube 16, the hole-holding tube is pulled up and separated in parallel with the injection of the grout material.
[0056]
As described above, in the double tube drilling method of the present invention, the solid rock bolt 14 provided with the lost bit 12 at the tip is provided with the drilling rod to which the rotational force from the drifter 22 and the striking force are applied. Have been used.
[0057]
The solid lock bolt 14 can sufficiently secure the same rigidity even if it has a smaller diameter than the hollow self-drilling lock bolt. If the inner diameter of the lock bolt 14, that is, the inner hole of the hole-drilling double pipe 18, is small, the hole-holding pipe 16 serving as the outer can also be sufficiently reduced in diameter. According to, it is enough.
[0058]
That is, according to the double pipe drilling method of the present invention using the solid rock bolt 14 as a drilling rod, the drilling diameter can be sufficiently reduced, and the drilling time can be reduced by reducing the drilling diameter. By sufficiently shortening the work, the workability is surely improved.
[0059]
Further, the lock bolt 14 is sufficient as a standard product, and the hole retaining tube 16 to which an excessive force is not applied at the time of drilling is sufficient if it has a purpose of protecting the hole wall. That is, since these member costs can be reduced, the work cost itself is sufficiently reduced.
[0060]
Further, in the present invention, the fluid from the fluid swivel 28 is sent around the lock bolt 14 in the hole holding pipe 16 through the through channel of the adapter 32 and discharged from the tip of the hole holding pipe to the outside thereof. By doing so, since so-called reversion is performed in which the drilling slime at the bottom of the hole is discharged from the hole opening along the outer peripheral surface of the hole-holding tube, smooth discharge of the drilling slime can be easily ensured.
[0061]
In the present invention, the hole holding pipe 16 is directly connected to the fluid swivel 28, so that the hole holding pipe is used as a grout injection pipe. According to this configuration, since it is not necessary to use a separate injection tube, that is, a grout hole, the workability is reliably improved.
[0062]
And if it is the drilling double pipe structure 10 of this invention, the operation | work through the opening window 52 of a hole-holding pipe coupler can perform the isolation | separation / connection operation | movement of the lock bolt 14 easily, and this opening By sealing the window with the outer tube 54, it is possible to ensure a smooth flow of fluid without leakage, and according to this drilled double tube structure, the above-mentioned double tube drilling method can be appropriately performed. Become.
[0063]
Here, in the embodiment of the present invention, the hole-holding pipe coupler 52 has a double pipe structure, and the outer pipe 54 is used to seal the opening window 52 of the inner pipe. However, the present invention is not limited to this. For example, it is possible to seal the opening window by attaching a cover body having a corresponding shape by screwing or the like. This configuration may be used in this hole-holding pipe coupler.
[0064]
However, if the outer tube 54 of the double tube is used as the cover body as in this embodiment, the hole-holding tube coupler 52 that does not complicate the configuration and the opening and sealing operations can be easily secured. .
[0065]
The above-described embodiments are for explaining the present invention, and do not limit the present invention. All modifications, alterations, and the like within the technical scope of the present invention are included in the present invention. It goes without saying that it is done.
[0066]
【The invention's effect】
As described above, according to the double bolt drilling method of the lock bolt according to the present invention, the solid lock bolt provided with the lost bit at the tip is used as the drilling rod. It is possible to sufficiently reduce the diameter of the hole without being accompanied. Therefore, the workability is surely improved by sufficiently reducing the drilling time by reducing the drilling diameter.
[0067]
A standard product is sufficient for the lock bolt, and a hole-holding tube to which an excessive force is not applied at the time of drilling is sufficient if it has a purpose of protecting the hole wall. That is, since these member costs can be reduced, the work cost itself is sufficiently reduced.
[0068]
Further, in the present invention, the fluid from the fluid swivel is sent around the lock bolt in the hole holding tube through the through-flow channel of the adapter, and is discharged to the outside from the hole holding tube tip portion. Since the bottom drilling slime is discharged from the hole opening along the outer peripheral surface of the hole-holding tube, so-called reversal is performed, so that smooth discharge of the drilling slime can be easily ensured.
[0069]
In the present invention, the hole-holding tube is directly connected to the fluid swivel so that the hole-holding tube is used as a grout injection pipe. That is, the grout material can be injected into the drilling hole without using a separate injection tube or the like, so that the workability can be improved with certainty.
[0070]
With the drilled double pipe structure of the present invention, the work through the opening window of the hole-holding pipe coupler makes it easy to detach / connect the lock bolt inside, and covers this opening window. By sealing with a body, smooth fluid flow without leakage can be ensured, and according to this drilled double pipe structure, the above-mentioned double pipe drilling method can be performed appropriately.
[0071]
Furthermore, if the hole-holding pipe coupler has a double-pipe structure and the outer pipe is used as a cover body for the opening window provided in the inner pipe, the hole-holding pipe coupler that does not complicate the configuration, its opening and sealing operations. Can be secured easily.
[0072]
Further, if the male thread part of the hole-holding tube can be directly screwed into the female thread part of the hollow rotating body of the fluid swivel, the hole-holding pipe can be connected to the fluid swivel smoothly and easily.
[Brief description of the drawings]
FIG. 1 is a partially broken side view of a drilled double pipe and a boring machine showing a drilled double pipe structure according to the present invention.
FIG. 2 is a schematic partial side view of a drilled double pipe structure when an opening window of a hole-holding pipe coupler is sealed and opened.
FIG. 3 is a partially exploded perspective view of a drilled double pipe structure.
FIG. 4 is a schematic side view of the adapter with a part broken away.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Double drilling pipe structure 14 Rock bolt 16 Hole holding pipe 28 Fluid swivel 32 Adapter 42 Hole holding pipe coupler 52 Opening window

Claims (6)

Using a solid rock bolt with a lost bit at the tip and a hole-holding pipe that surrounds and surrounds almost the entire length of this rock bolt as an inner and outer of a drilled double pipe, it has a rotating function and a striking function. Double pipe drilling with a boring machine,
A hollow rotary body of a fluid swivel is fixedly screwed to a drive shaft of a drifter that can move forward and backward, which is a rotation / blow drive device of a boring machine, and a through-flow in the axial direction with respect to this hollow rotary body The lock bolt is fixedly screwed through an adapter having a path so that the lock bolt functions as a drilling rod to which a driving force is applied from the rotary drive shaft,
Connected to the outer connection port of the fluid swivel through a hole-holding pipe coupler having a sealable open window, inside the hole-holding pipe that is synchronously inserted into the hole following the excavation progress of the lock bolt, A lock bolt that can secure the reversal of the drilling slime along the outer peripheral surface of the hole holding pipe by sending the fluid from the fluid swivel through the flow path of the adapter and discharging the fluid from the tip of the hole holding pipe to the outside. Double pipe drilling method. After excavation to the planned depth, the hole-retaining pipe and the lock bolt in the hole are removed from the fluid swivel together with the respective hole-retaining pipe coupler and adapter, and the hollow rotating body after the adapter is removed. On the other hand, the double tube drilling method of the rock bolt according to claim 1, wherein the grout material is injected into the drilling hole by directly connecting the holding tube in the drilling hole. . The double tube drilling method for a lock bolt according to claim 2, wherein the hole holding tube is pulled up and separated sequentially in parallel with the injection of the grout material. A solid lock bolt with a lost bit at the tip and a retaining tube that surrounds and surrounds almost the entire length of this lock bolt as an inner and outer of a drilled double tube, and has a rotation function and a striking function. Is a drilling double pipe capable of double pipe drilling by a drilling machine,
A fluid swivel having a hollow rotating body connected to a drive shaft of a drifter capable of advancing and retreating as a rotation / blow driving device of a boring machine;
The fluid swivel is fixedly connected to the hollow rotating body of the fluid swivel under the screwing, and an axial through-flow passage communicating with the hollow rotating body is formed around the female screw recess to which the lock bolt is screwed. A hollow rotating body, an adapter functioning as a joint member between the lock bolts;
The connection end connected to the outer connection port of the fluid swivel under the fitting, and the female thread portion of the male thread portion formed at the rear end of the hole-holding tube, the hollow rear end of the tubular body, and the hollow A fluid around the lock bolt is provided at each front end, and a cover body that opens and seals the opening window partially defined and formed on the peripheral surface thereof is movably provided with respect to the tubular body. A hole-holding pipe coupler that functions as a joint between the swivel and the hole-holding pipe;
Comprising
By connecting the solid lock bolt to the rotation drive shaft of the boring machine's drifter so as to be integrally rotatable via a hollow rotating body of the fluid swivel and an adapter, the lock bolt functions as a drilling rod, The fluid sent from the fluid swivel to the inside of the hole holding pipe through the adapter through-flow channel is discharged to the outside from the hole holding pipe tip, so that the drilling slime can be turned over along the outer circumference of the hole holding pipe. Drilled double pipe structure. The hole-holding pipe coupler is a combination of an inner pipe as a tubular body; and an outer pipe as a cover body disposed around the inner pipe so as to be slidable in the axial direction with respect to the inner pipe. It has a double pipe structure, and by inserting a tool through an opening window formed in this inner pipe, it is possible to separate the lock bolt in the hole-holding pipe coupler or to hold the lock bolt when connecting. The drilled double pipe structure according to claim 4. 6. The drilled double pipe structure according to claim 4 or 5, wherein the male thread portion of the hole-holding tube is formed so as to be directly screwable with the female thread portion of the hollow rotating body of the fluid swivel.

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