JP2004169436A - Double tube excavation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double tube excavation system capable of using an ordinary bit without using a widening bit or a lost bit (throwaway bit) even in excavation of an excavation rod of a double tube and applying double tube excavation of a down-the-hole hammer capable of imparting a rotary force and a thrust to the external tube (casing), and further smoothly discharging slime. <P>SOLUTION: In an excavation rod having a double-walled structure composed of an internal pipe connected to a drive and to which a rotary force and a thrust, a striking force and a thrust, or a rotary force, a striking force, and a thrust are transmitted, and an external pipe in which the internal pipe is inserted, in a free state, the external pipe is attachably/detachably engaged with the internal pipe in the vicinity of the upper end of the external pipe. The rotary force and the thrust, the striking force and the thrust, or the striking force and the thrust or the rotary force, the striking force, and the thrust transmitted to the internal pipe are transmitted to the external pipe through the engagement part with the internal pipe, in this excavation rod of the double-walled structure. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a double pipe drilling system used for construction such as anchor and ground improvement, and more particularly to a double pipe drilling system suitable for use in a down-the-hole drill.
[0002]
[Prior art]
BACKGROUND ART Conventionally, there is known a down-the-hole drill in which a hitting device having a built-in down-the-hole hammer is provided on the tip side of a drilling rod, and a hitting force is applied to a bit by the hitting device. In this down-the-hole drill, drilling may be disrupted due to drilling with a single-pipe drilling rod. In such a case, a double-pipe down-the-hole drill using a casing has been proposed.
[0003]
FIG. 8 is an explanatory view showing a conventional example of a down-the-hole drill using this double pipe. An inner pipe 22 and an outer pipe 23 constituting a double pipe 21 are connected to a drifter 24, and a tip side of the inner pipe 22. Is provided with a striking device 28 having a built-in down-the-hole hammer, and a swivel 27 is provided above the double pipe 21. Compressed fluid is supplied through the swivel 27 through the inner pipe 22 to operate the down-the-hole hammer. Then, a striking force is applied to the inner bit 25, and the rotational force and the thrust are applied from the drifter 24. At this time, there is a type in which compressed fluid is ejected from the inner bit 25 and slime is discharged from the discharge passage 29 between the inner pipe 22 and the outer pipe 23.
[0004]
As such a down-the-hole drill, a bit with an enlargement / reduction function is used for the bit at the tip of the down-the-hole drill, and when drilling, a hole having a larger diameter than the casing (outer pipe) that expands and follows the bit is used. When drilling and pulling up the inner pipe, a method of reducing the diameter of the bit (for example, see Patent Literature 1) and a method of discarding a bit at the tip of a down-the-hole drill using a discard bit to form a hole larger in diameter than the casing (outer pipe) that follows. There is a method of excavating and excavating a drilling rod, in which a bit is cut off and discarded at the bottom of a hole (for example, see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent No. 2574705 [Patent Document 2]
JP 2002-138786 A
[Problems to be solved by the invention]
However, the use of a bit having an enlargement / reduction function at the tip of a drilling rod has a movable part for enlarging / reducing the bit portion where the load is the largest. The problem that malfunctions are likely to occur, the disadvantage that the bit shape is complicated and the cost is high, and the outer pipe (casing) is stopped by the bit at the tip of the inner pipe, and the excavation depth is limited because it is carried along with this. In addition, the vertical movement of the inner pipe is limited, and it takes time to connect and disconnect the outer pipe and the inner pipe.
[0007]
In addition, the use of a discard bit that discards the bit at the bottom of the hole is made by using a material of a material that can withstand the rotating bit and the striking force because the bit is used to drill the ground. There is a problem that it is not inexpensive, and the number of holes to be drilled is large, so that the number of bits to be discarded for each hole becomes large, resulting in a large economical burden.
[0008]
Further, in a system in which the slime discharge passage 29 is provided between the inner tube 22 and the outer tube 23 as shown in FIG. 8, the upper end (end) of the discharge passage 29 is closed by a drifter. The gas is discharged from a discharge hole provided in 27. However, since the number and size of the discharge holes provided in the swivel 27 are limited, it is difficult to completely discharge the slime only by the discharge holes provided in the swivel 27, and the discharge amount of the slime is smaller than that of the swivel 27. When the amount exceeds the discharge amount, the slime accumulates in the discharge passage 29 and acts as a frictional force on the rotation of the inner tube 22 during drilling, which has a problem of adversely affecting the rotation of the inner tube 22.
[0009]
The present invention has been made in view of such a problem, and an object of the present invention is to use a normal bit without using an enlarged bit or a discarded bit even when excavating a double pipe drilling rod. To provide a double-pipe drilling system that can apply a rotating force and thrust to the outer pipe (casing) from the ground, and that can perform double-pipe drilling of a down-the-hole hammer and can also smoothly discharge slime. is there.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, a double pipe excavating system according to the present invention includes an inner pipe connected to a driving unit and transmitting torque and thrust or impact and thrust or torque, torque and thrust, and an inner pipe. A drilling rod having a double-pipe structure comprising an outer pipe inserted in a free state and an outer pipe, wherein the outer pipe is detachably engaged with the inner pipe near its upper end and transmitted to the inner pipe. It is characterized by comprising a drilling rod having a double pipe structure in which the rotating force and the thrust or the striking force and the thrust or the rotating force, the striking force and the thrust are transmitted to the outer pipe through the engaging portion with the inner pipe.
The down-the-hole hammer that can use a normal bit without using an enlarged bit or a discard bit even when excavating a double pipe, and can apply rotational force and thrust to the outer pipe (casing) from the ground. Double pipe excavation becomes possible. Also, slime can be discharged smoothly because the upper end opening of the outer tube can be used.
[0011]
Further, in the double pipe excavating system of the present invention, the configuration in which the outer pipe is detachably engaged with the inner pipe is provided on one outer wall or the inner wall of the inner pipe and the outer pipe with spline engagement. The projection is characterized in that it is configured to fit into and engage with a concave groove or notch provided on the other inner or outer wall.
Thereby, the outer tube can easily engage the vicinity of the upper end with the inner tube.
[0012]
Further, in the double pipe excavating system of the present invention, in the engagement portion where the outer pipe is detachably engaged with the inner pipe, the striking force transmitted to the inner pipe is vertically transmitted to the outer pipe. It is characterized in that a striking surface is provided to abut.
Thereby, the impact force from the inner pipe is efficiently and reliably transmitted, and the drilling efficiency is improved.
[0013]
Further, the double pipe excavating system according to the present invention is characterized in that a hitting device having a built-in down-the-hole hammer is provided at a distal end side of the inner pipe.
This makes it possible to perform double pipe excavation in which a hitting force is applied to the inner pipe by the down-the-hole hammer.
[0014]
Further, the double pipe excavating system of the present invention is characterized in that the inside of the inner pipe serves as a supply passage for compressed fluid, and the space between the inner pipe and the outer pipe serves as a slime discharge passage.
This allows slime to be discharged. In addition, since drilling can be performed while sending a compressed fluid (water or air), drilling efficiency is further improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic explanatory view showing an example of a drilling device, FIG. 2 is a sectional explanatory view showing an embodiment of the present invention, FIG. 3 is a perspective view showing a main part of the embodiment of the present invention, and FIG. FIG. 5 is a perspective view of a main part showing an operation state of the embodiment of the present invention, and FIG. 5 is a cross-sectional view of a main part showing an operation state of the embodiment of the present invention.
[0016]
In a drilling apparatus 10 shown in FIG. 1, a driller (drill head) 11 as a drive unit is provided so as to be able to advance and retreat along a guide cell 12, and the drill rod 1 is connected to the driller 11 via a swivel 13 to perform drilling. A bit 4 is connected to the tip of the rod 1, and the bit 4 is provided with a rotating force and a thrust or a striking force and a thrust or a rotating force, a striking force and a thrust through the excavating rod 1 by a driller 11, and drills the hole. Is what you do.
[0017]
The excavating rod 1 has a double pipe structure of an inner pipe 2 and an outer pipe 3 as shown in FIG. 2, and the inner pipe 2 is connected to a drifter 11 through a coaxial double pipe swivel 13, and the outer pipe 3 Are engaged with the inner pipe 2 in the swivel 13. In the engagement structure between the inner tube 2 and the outer tube 3, as shown in FIG. 3, protrusions 7 are provided on the outer wall of the inner tube 2, and the protrusions 7 are fitted into the inner wall of the outer tube 3. When the projections 7 are fitted into the grooves 8, they engage with each other with respect to the rotation of the inner tube 2, and the rotation of the inner tube 2 is transmitted to the outer tube 3. Has become. That is, the outer tube 3 is free to rotate, and the rotational force from the drifter 11 is transmitted only to the inner tube 2, and is transmitted to the outer tube 3 from the inner tube 2. The protrusion 7 and the concave groove 8 may be provided with a concave groove 8 on the outer wall of the inner tube 2 and a protrusion 7 fitted on the inner wall of the outer tube 3.
[0018]
In addition, the engagement structure between the inner tube 2 and the outer tube 3 may be a notch 9 into which the projection 7 is inserted instead of the concave groove 8 as shown in FIG. Also in this engagement structure, the rotational force of the inner tube 2 is transmitted to the outer tube 3 by mutually engaging with the rotation of the inner tube 2, and the rotational force of the outer tube 3 in the free state is transmitted from the inner tube 2. Can be rotated. Further, the engagement structure between the inner tube 2 and the outer tube 3 may be a spline engagement.
[0019]
FIG. 4 shows a state in which the protrusion 7 provided on the outer wall of the inner tube 2 is fitted into a concave groove 8 provided on the inner wall of the outer tube 3, and FIG. Is fitted into the concave groove 8 of the outer pipe 3, and when the inner pipe 2 rotates, the projection 7 of the inner pipe 2 comes into contact with the end 8 a of the concave groove 8 of the outer pipe 3, and the rotational force of the inner pipe 2 is reduced. The manner in which it is transmitted to the tube 3 is shown.
[0020]
The excavating rod 1 has an inner bit 5 at the tip of the inner tube 2 as a bit 4 and an outer bit 6 at the tip of the outer tube 3. In the excavating rod 1, the inside of the inner pipe 2 is a supply passage 2a for compressed fluid, and the space between the inner pipe 2 and the outer pipe 3 is a slime discharge passage 3a.
[0021]
When the inner pipe 2 is rotated by the drifter 11, the projection 7 of the inner pipe 2 is fitted into and engaged with the concave groove 8 of the outer pipe 3. Is also transmitted to the outer tube 3 and the outer tube 3 also rotates. At this time, when a compressed fluid (water or air) is supplied from the supply passage 2a via the swivel 13, the compressed fluid is ejected from the inner bit 5 at the tip of the inner pipe 2, and this fluid is accompanied by slime. It is discharged from the discharge passage 3a via the swivel 13. Thus, the drilling rod 1 composed of the inner pipe 2 and the outer pipe 3 can be drilled by rotating while extruding fluid from the inner bit 5 at the tip of the inner pipe 2.
[0022]
Further, if the engagement structure of the inner tube 2 and the outer tube 3 is employed as described above, the restriction on the attachment of the outer tube 3 to the swivel 13 is reduced, and the number of discharge holes of the swivel 13 is increased, and the diameter of the swivel 13 is increased. Therefore, slime can be discharged well. As a result, the slime is reliably discharged without accumulating in the discharge passage.
[0023]
Further, if the drifter 11 is capable of imparting a rotating force and a striking force like a rotary percussion drill, not only the rotating force but also the striking force can be imparted to the inner tube 2. In this case, the inner pipe 2 can be rotated and hit while ejecting fluid from the inner bit 5 at the tip of the inner pipe 2, and the outer pipe 3 can be rotated for drilling.
[0024]
Further, if the engagement structure between the projection 7 and the concave groove 8 or the notch 9 is a structure in which the rotational force and the striking force applied to the inner tube are also transmitted to the outer tube 3, the rotational force is also applied to the outer tube 3. And impact power.
For example, a striking surface 8b or 9b on which the protrusion 7 of the inner tube 2 abuts in the vertical direction is provided in the concave groove 8 or the notch 9 of the outer tube 3 as shown in FIGS. The applied striking force is transmitted to the outer tube 3 via the striking surface 8b or 9b. As a result, the rotational force and the impact force applied to the inner pipe 2 can be applied to the outer pipe 3. Further, even if the outer tube 3 is spline-engaged with the inner tube 2, a rotational force and a striking force can be applied to the outer tube 3.
[0025]
FIG. 7 is an explanatory sectional view showing another embodiment of the present invention. In this example, a drilling rod 1 composed of an inner pipe 2 and an outer pipe 3 has an inner pipe 2 connected to a drifter 11 via a swivel 13, and a hitting device 14 having a built-in down-the-hole hammer at the tip end of the inner pipe 2. Are provided to form a down-the-hole drill, and the other components are the same as those of the above-described embodiment. Therefore, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.
[0026]
According to this embodiment, a rotational force can be applied to the inner tube 2 by the drifter 11 and a striking force can be imparted to the inner tube 2 by the striking device 14. The rotational force and the striking force applied to the inner pipe 2 can be transmitted to the outer pipe 3 by the above-described engagement structure of the protrusion 7 and the concave groove 8 or the notch 9. The same applies to spline engagement. As a result, the compressed fluid is supplied through the inner pipe 2 as a supply passage, and the down-the-hole hammer of the impact device 14 is operated, and the rotational and impact forces are applied to the inner pipe 2 and the outer pipe 3 while squirting from the inner bit 5. Can be drilled. At this time, according to the engagement structure of the inner tube 2 and the outer tube 3 of the present invention as described above, the upper end of the outer tube 3 can be opened without being connected to the swivel 13 as shown in FIG. it can. This ensures that the slime does not accumulate in the discharge passage 3a and does not act on the rotation of the inner tube 2 as a frictional force.
[0027]
The above embodiments do not limit the present invention, and the present invention allows various modifications without departing from the scope of the invention. For example, the present invention can be applied to any drilling device that applies a turning force and a thrust or a striking force and a thrust or a turning force, a striking force and a thrust. Further, the present invention can be applied without supplying compressed fluid (drilling fluid).
[0028]
【The invention's effect】
As described in detail above, the double pipe excavating system of the present invention has the following effects.
(1) The excavating rod is composed of a double pipe consisting of an inner pipe and an outer pipe. Since the outer pipe receives rotational force, impact force and thrust from the inner pipe at the upper end, the outer pipe is driven by a drive unit (drifter). ) Is not required. In addition, even when excavating a double pipe, a normal bit can be used without using an expanding bit or a discard bit (lost bit), and a rotating force and thrust are applied to the outer pipe (casing) from the ground. Double-hole drilling of the down-the-hole hammer that can be done becomes possible.
[0029]
(2) The drilling rod is composed of a double pipe consisting of an inner pipe and an outer pipe, and the upper pipe (rear end) of the outer pipe transmits rotational force, impact force, and thrust from the inner pipe to the outer pipe. Since there is no restriction on the configuration of the inner bit and the outer bit at the tip of the tube and the outer tube, there is no need to use a diameter-enlarging bit or a lost bit (discard bit). Accordingly, the economic burden is reduced by this amount, and there is no need to lock or release the inner bit and the outer bit, so that the configuration is simplified and the cost is reduced.
[0030]
(3) According to the drilling rod having the engagement structure of the inner pipe and the outer pipe of the present invention, since the outer pipe does not need to be mounted on the swivel or the drive unit (drift), there are few restrictions on the mounting of the outer pipe on the swivel. Become. For this reason, the number of discharge holes of the swivel can be increased or the diameter of the swivel can be increased, so that the slime can be discharged well, and the slime does not accumulate in the discharge passage. It does not act as force. In particular, since the outer tube does not need to be attached to the drive unit, the upper end (rear end) can be left open, and in this case, the slime can be more efficiently discharged.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an example of a drilling device.
FIG. 2 is an explanatory sectional view showing an embodiment of the present invention.
FIG. 3 is a perspective view showing a main part of the embodiment of the present invention.
FIG. 4 is an essential part perspective view showing an operation state of the embodiment of the present invention.
FIG. 5 is a cross-sectional view of a main part showing an operation state of the embodiment of the present invention.
FIG. 6 is a perspective view showing a main part of another embodiment of the present invention.
FIG. 7 is an explanatory sectional view showing still another embodiment of the present invention.
FIG. 8 is an explanatory sectional view showing a conventional example. .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drilling rod 2 Inner tube 2a Compressed fluid supply passage 3 Outer tube 3a Slime discharge passage 4 Bit 5 Inner bit 6 Outer bit 7 Projection 8 Recessed groove 8a Recessed groove end 8b Recessed groove hitting surface 9 Notch 9a Notch end Part 9b Notch hitting surface

Claims (5)

An inner pipe connected to the drive unit and transmitting the rotational force and the thrust or the striking force and the thrust or the rotational force, the striking force and the thrust, and an outer pipe inserted into the inner pipe and in a free state; A drilling rod having a heavy pipe structure, wherein the outer pipe is detachably engaged with the inner pipe near its upper end, and the rotational force and thrust transmitted to the inner pipe or the striking force and thrust, or the rotational force, thrust and thrust transmitted to the inner pipe. Is provided with a drilling rod having a double pipe structure that is transmitted to the outer pipe via the engagement portion with the inner pipe. The structure in which the outer pipe is detachably engaged with the inner pipe may be a spline engagement or a projection provided on one outer wall or inner wall of the inner pipe and the outer pipe may be provided on the other inner wall or outer wall. The double pipe drilling system according to claim 1, wherein the double pipe drilling system is configured to be fitted into and engaged with the concave groove or notch. The outer tube is provided with a striking surface in which the outer tube is detachably engaged with the inner tube, the striking surface transmitting the striking force transmitted to the inner tube to the outer tube in a vertical direction. The double pipe drilling system according to claim 1 or 2, wherein: The double pipe drilling system according to any one of claims 1 to 3, wherein a hitting device having a built-in down-the-hole hammer is provided on a tip side of the inner pipe. The double pipe drilling system according to any one of claims 1 to 4, wherein the inside of the inner pipe serves as a supply passage for a compressed fluid, and the space between the inner pipe and the outer pipe serves as a slime discharge passage. .

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