JP4162136B2 - Double pipe drilling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, a fluid hammer having a diameter-expanding bit at its tip is disposed in the outer casing, and the inner rod that supports the fluid hammer is imparted with a rotational force from the rotational drive mechanism. The present invention relates to a double pipe drilling device using a diameter bit method.
[0002]
[Prior art]
As one of drilling methods for the ground or rock (such as ground), for example, there is a so-called double pipe drilling with a casing pipe and a hollow inner rod, and a double pipe for performing this double pipe drilling. As a hole drilling device, for example, a device capable of applying a striking force by a fluid hammer disposed in an outer casing to a bit at the tip in addition to a rotating force by a rotation drive mechanism is known. A configuration in which a so-called diameter-expanding bit, which can be switched between a diameter-expanded and a diameter-reduced depending on the rotation direction, is disposed at the tip of a fluid hammer is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-231085.
[0003]
An air-type down-the-hole hammer is generally used as the fluid hammer, and an inner rod is also used as a compressed air supply path serving as a drive source for the hammer.
[0004]
The outer diameter of the diameter-enlarged bit when reduced is smaller than the inner diameter of the outer casing. The diameter expansion bit is accommodated. Then, under the rotational drive in the excavation direction by the rotational drive mechanism, the diameter expansion bit is expanded, and the rotation outer diameter of the diameter expansion bit is set larger than the outer diameter of the outer casing. Thus, it is possible to ensure the progress of the outer casing following the progress of excavation of the diameter expanding bit.
[0005]
[Problems to be solved by the invention]
By the way, when drilling with a double pipe, a single double pipe is added each time as the drilling progresses. Normally, the existing double pipe is temporarily disconnected from the double pipe swivel provided on the rotary drive mechanism side, and a single double pipe, that is, an inner rod and an outer casing are respectively interposed and connected therebetween. Thus, the additional double pipe is added to the existing double pipe.
[0006]
Here, the separation operation between the existing double pipe and the double pipe swivel is usually performed by the following procedure.
[0007]
In the separation between the existing double pipe and the double pipe swivel, the outer casing and the double pipe swivel are usually separated first. Since the connection between the outer casing and the double pipe swivel is a screw connection between the corresponding screw parts, the disconnection between them is performed under the screw separation between the screw parts.
[0008]
When the outer casing and the double pipe swivel are separated by screwing, the double pipe swivel is screwed with respect to the outer casing, so that the inner rod still connected to the double pipe swivel is As the tube swivel is screwed, the amount corresponding to the screwing is raised. That is, when the outer casing and the double tube swivel are separated by screwing, it is required to consider the lifting of the inner rod accompanying the screwing and separation.
[0009]
Normally, after the diameter-reduction by rotation (reverse rotation) of the diameter-enlarged bit in a state where the diameter-enlarged bit is pressed against the bottom of the hole, that is, after enabling the diameter-enlarged bit to be pulled into the outer casing, The threaded separation between the outer casing and the double tube swivel is performed. However, if the diameter reduction bit of the diameter expansion bit is obstructed by the drilling slime or the like retained at the bottom of the hole, the diameter expansion bit in the diameter expansion state is engaged with the tip of the casing, and the tensile torque when the double pipe swivel is retracted. Under these circumstances, since the enlarged bit is pressed against the tip of the outer casing, it is inevitable that the outer casing is damaged and the enlarged bit is damaged.
[0010]
Further, when the diameter expanding bit is engaged with the tip of the outer casing, further pulling of the inner rod, that is, screwing of the double pipe swivel with respect to the outer casing is hindered, so that the separation operation itself becomes difficult.
[0011]
However, in the known configuration, it is not easy to determine from the outside whether or not the diameter-enlarged bit has been reliably reduced in diameter. Usually, the double-tube swivel can be separated from the outer casing by screwing. Since it is the present condition that there is no choice but to judge based on the result, it is unavoidable that the known configuration is inferior in terms of safety, workability, and the like.
[0012]
An object of the present invention is to provide a double-pipe drilling device that secures the safety of the diameter expansion bit, the outer casing tip, and improves the workability when separating the outer casing and the double-pipe swivel.
[0013]
[Means for Solving the Problems]
In order to achieve this object, according to the double pipe drilling device of the first aspect of the present invention, a hollow main body rod having a through-passage and a part of the main body rod in the main body rod with rotation restriction are provided. An inner joint unit having an inserted slide rod as an expandable and contractible tubular body, and an outer tubular adapter corresponding to the shortened length of the joint unit and capable of separating and surrounding the joint unit The supplementary double pipe as a combination of the inner pipe and the threaded connection between the opposite threaded portions of the outer casing and the double pipe swivel between the double pipe swivel and the existing double pipe. Is intervened. And, under the lock of the locking means that makes the main body rod and the slide rod unable to expand and contract under the engagement, it is possible to regulate the extension of the joint unit from the shortened state, and the locking means By unlocking, it is possible to guarantee the extension of the joint unit.
[0014]
According to a second aspect of the present invention, of the slide rods of the joint unit, the thin tube portion on the double tube swivel side loosely inserted into the main body rod is provided with radial linear protrusions extending in the axial direction thereof. The main body rod has a spline shaft formed on its peripheral surface, and an adapter having a spline groove corresponding to this spline shaft on its inner peripheral surface is fixedly disposed on the inner rod side end of the main body rod. The rotation regulation of the slide rod can be ensured.
[0015]
Furthermore, according to a third aspect of the present invention, the spline shaft of the slide rod is formed to have a circumferential protrusion partially protruding in the one circumferential direction, and the adapter of the main body rod is connected to the spline shaft. A fitting recess into which the circumferential projection can be fitted is provided continuously to the spline groove, and a combination of the circumferential projection and the fitting recess is embodied as the locking means. Then, by making the locking direction of the locking means coincide with the diameter increasing rotation direction of the diameter expanding bit, it is possible to ensure unlocking of the locking means accompanying the diameter reduction of the diameter expanding bit.
[0016]
Further, in claim 4 of the present invention, a through-hole in the direction perpendicular to the axis provided in the outer tubular adapter, a circumferential locking groove provided in the peripheral surface of the slide rod, A combination with a lock pin that is inserted into and engaged with the lock groove of the slide rod by penetration through the through hole from the outside of the tubular adapter is embodied as a lock means.
[0017]
According to claim 5 of the present invention, a seal member for sealing the periphery of the slide rod is fixedly disposed at the end portion of the double tube swivel so that the slide rod can be removed from around the slide rod. It is possible to prevent leakage of fluid.
[0018]
Further, in claim 6 of the present invention, the seal member is embodied as a combination of a substantially cylindrical main body that can be mounted on the slide rod and an O-ring mounted around the main body.
[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 double pipe drilling device 10 according to the present invention, an existing double pipe 16 as a combination of a hollow inner rod 12 and an outer casing 14 surrounding and surrounding the inner rod 12 is provided. It is connected to and supported by a double pipe swivel 22 provided in the rotation drive mechanism 20 of the drilling device body 18. The double-pipe drilling apparatus 10 is embodied as a so-called diameter-expanding bit system in which a diameter-expanding bit 26 is provided on the fluid hammer 24 in the outer casing 14.
[0021]
The rotary drive mechanism 20 of the drilling device main body is formed so as to be able to rotate the hollow rotary body 28 of the double-pipe swivel 22, for example, and the inner rod 12 is applied by applying rotational force from the rotary drive mechanism. Is rotated in its driving direction.
[0022]
In addition, as this kind of drilling apparatus main body 18, the general rotary boring machine for double pipe drilling etc. can be illustrated.
[0023]
In the double-pipe drilling device 10 of the present invention, in addition to the rotational force from the rotational drive mechanism portion 20, the striking force by the fluid hammer 24 arranged at the tip of the inner rod 12 is applied to the diameter expansion bit 26. By applying, drilling propulsion is ensured by both rotation and impact.
[0024]
As this fluid type hammer 24 disposed in the outer casing 14, for example, a down-the-hole hammer using a fluid such as compressed air or high-pressure water as a drive source can be used. These fluids include a compressor or a high-pressure pump. The fluid supply source 30 supplies the fluid from the hollow rotating body 28 of the double tube swivel 22 through the flow path in the inner rod 12 to the fluid hammer at the tip.
[0025]
In addition, the basic structure itself of the double pipe drilling device that drills holes by the bit by applying the striking force by the fluid hammer in the outer casing to the bit in addition to the rotational force by the rotation drive mechanism part is as follows. For example, since it is known as disclosed in Japanese Patent Laid-Open No. 5-231085 and the like, a detailed description of this basic configuration is omitted here.
[0026]
The diameter expansion bit 26 provided in the fluid hammer 24 is provided so as to protrude outward from the front end of the outer casing 14 as shown in FIG. And this diameter expansion bit 26 is comprised as what switches a diameter expansion and a diameter reduction according to the rotation direction.
[0027]
The diameter-enlarged bit 26 is smaller than the inner diameter of the outer casing 14 and is rotated in a specific direction from a reduced diameter state as shown by a one-dot chain line in FIG. The rotating diameter is increased to a rotational outer diameter larger than the outer diameter of the inner diameter of the inner rod 12 through the double-tube swivel 22 from the rotational drive mechanism 20 (see FIG. 2). Defined as hole rotation direction.
[0028]
In the diameter-expanding bit 26, if the inner rod 12 rotates (reverses) in the direction opposite to the diameter-expanding rotation direction (the direction of the one-dot chain line in FIG. 1), the outer diameter of the outer casing 14 The diameter is reduced to be smaller than the inner diameter (see the dashed line in FIG. 1).
[0029]
In addition, since this kind of diameter expansion bit 26 is not the meaning of this invention, and only the commercially available well-known thing can be utilized as this diameter expansion bit, the detail of this diameter expansion bit is demonstrated here. do not do.
[0030]
By the way, the double pipe used in this type of double pipe drilling apparatus 10, that is, the inner rod 12 and the outer casing 14, are all formed as single bodies of a specific length, and these single bodies are formed as the excavation depth of the hole 32. If necessary, it is possible to construct a double pipe having a length corresponding to the depth of excavation.
[0031]
The expansion of the double pipe, that is, the addition of the additional double pipe to the existing double pipe 16 inserted into the drilling hole, is usually performed after the double pipe swivel 22 is once disconnected from the existing double pipe, and then the existing two pipes. It is performed between the heavy pipe and the double pipe swivel.
[0032]
Here, as can be seen from FIG. 1, in the present invention, the hollow body rod 34 and the slide rod 36 partially inserted into the body rod with rotation restriction are extendable and retractable. A supplementary double pipe as a combination of an inner joint unit 38 formed as a tubular body and an outer tubular adapter 40 corresponding to the shortened length of the joint unit and capable of separating and enclosing the joint unit 42 is interposed between the double pipe swivel 22 and the existing double pipe 16 under the threaded connection between the inner rod 12 and the opposite threaded portions of the outer casing 14 and the double pipe swivel. Yes.
[0033]
As can be seen from FIG. 4 in addition to FIG. 3, the main body rod 34 of this joint unit is a hollow body having a through-passage 44, and its end on the double tube swivel side (the right end in the figure). However, since it is provided in the hollow rotating body 28 of the double tube swivel, it is formed as a male screw portion 34a corresponding to the screw portion 28a. Then, the slide rod 36 partially inserted into the main body rod 34 has a female thread portion 36a corresponding to the male thread portion 12a of the existing double pipe inner rod 12 as an end portion on the inner rod side (the left end in the figure). Part), the joint unit 38 having a combination of the main body rod 34 and the slide rod is interposed between the inner rod and the double pipe swivel under the screw connection between the screw parts. It is formed as a telescopic tubular body.
[0034]
Here, in the present invention, of the slide rods 36 of the joint unit, the thin tube portion 36b on the double tube swivel side loosely inserted into the main body rod 34 has radial linear protrusions 46 extending in the axial direction thereof. Is formed as a spline shaft having a peripheral surface thereof. An adapter 50 having a spline groove 48 corresponding to the linear protrusion 46 of the spline shaft (thin shaft portion) 36b on the inner peripheral surface thereof is provided on the inner rod side end portion (left end portion in the figure) of the main body rod 34. Fixedly arranged.
[0035]
Note that the fixed arrangement of the adapter 50 with respect to the main body rod 34 is performed, for example, under the threaded connection of the male screw portion 50a to the screw portion 34b because it is provided on the main body rod.
[0036]
According to such a configuration, the forward / backward movement of the slide rod 36 relative to the main body rod 34 is easily ensured. That is, according to this, the expansion / contraction performance as the joint unit 38 can be easily secured.
[0037]
Then, for example, the rotation of the slide rod 36 relative to the main body rod 34 can be reliably regulated under the engagement of the linear protrusion 46 of the spline shaft and the spline groove 48. That is, according to this configuration, it is possible to easily ensure the integral rotation of the main body rod 34 and the slide rod 36 in the joint unit 38 that is an expandable and contractible tubular body.
[0038]
Here, as can be seen from FIG. 3, in this joint unit 38, the seal member 51 that seals around the slide rod in the main body rod is provided at the end of the spline shaft 36 a of the slide 36 (double tube swivel). (Side end) 36b is fixedly arranged.
[0039]
As the seal member 51, for example, a substantially cylindrical main body 52 that can be mounted on the end of the double rod swivel side of the slide rod 36, and an annular recess 52a are fitted around the main body. A combination with the O-ring 54 can be exemplified, and by making the O-ring slide in contact with the through-passage 44 of the main body rod, it is possible to prevent leakage of fluid from around the slide rod in the main body rod.
[0040]
The seal member 51 is fixed to the slide rod 36, for example, with the stopper ring 56 screwed to the end portion of the thin shaft portion 36b of the slide rod.
[0041]
According to such a configuration, even though the joint unit 38 is a telescopic tubular body having a combination of the main body rod 34 and the slide rod 36, it is possible to reliably prevent leakage of the fluid flowing inside the joint unit 38. Become.
[0042]
In this embodiment, the combination of the substantially cylindrical main body 52 and the O-ring 54 is embodied as the seal member 51. However, around the slide rod 36 in the through-passage 44 of the main body rod, Since sealing is sufficient to prevent leakage, the present invention is not limited to this.
[0043]
However, with such a seal member 51, the reliable sealing can be easily ensured without complicating the configuration. And if it is the structure which arrange | positions the substantially cylindrical main body 52 around the thin shaft part 36b of a slide rod like this, this main body fixed by the stopper ring 56 will engage with the adapter 50 of a main body rod end part. Therefore, it is possible to sufficiently prevent the slide rod 36 from dropping from the main body rod.
[0044]
By the way, if the joint unit 38 is always expandable and contractible, there is a risk that smooth and reliable advance and retreat movement cannot be obtained when the inner rod 12 advances and retreats with respect to the outer casing 14. Therefore, in the present invention, the lock unit 58 is provided in the joint unit 38, and the expansion and contraction of the joint unit is controlled under the switching of locking and unlocking of the locking unit.
[0045]
As shown in FIGS. 3 and 4, as the locking means 58, for example, a linear protrusion 46 partially protruding in the circumferential direction provided on the spline shaft (thin shaft portion) 36b of the slide rod is used. The combination of the circumferential protrusion 60 and the fitting recessed part 62 provided in the adapter 50 of the main body rod which can insert a circumferential protrusion can be illustrated. In this configuration, the engagement direction of the circumferential protrusion 60 and the fitting recess 62, that is, the locking direction of the locking means 58 coincides with the diameter expansion rotation direction of the diameter expansion bit 26 (see FIG. 1). It is embodied as.
[0046]
The locking position by the locking means 58 can be embodied as the insertion limit position of the slide rod 36 relative to the main body rod 34, that is, the shortened state of the joint unit 38.
[0047]
That is, in this configuration, the locking means 58 is locked by applying a rotational force in the diameter increasing rotation direction of the diameter expanding bit 26 to the main body rod 34 in a state where the rotation of the slide rod 36 is restricted, and the joint unit is locked. 38 is regulated to be extended under the lock of the locking means. Then, if the main body rod 34 is rotated (reversely rotated) in the direction opposite to the diameter expansion rotation direction of the diameter expansion bit 26, the lock restriction of the lock means 58 is released, so that the expansion restriction of the joint unit 38 is released, and the slide rod 36 free slides can be secured.
[0048]
In this configuration, since the rotation of the main body rod 34 and the slide rod 36 is required for the stroke required for locking and unlocking of the locking means 58, the linear protrusion of the spline shaft is required. 46 and the width of the spline groove 48 are respectively set as widths corresponding thereto.
[0049]
The existing double pipe 16 from the double pipe swivel 22 in the double pipe drilling device 10 provided with the joint unit 38 having the lock means 58 of this configuration and the corresponding tubular adapter 40 as the supplementary double pipe 42. An outline of the separation procedure will be described below.
[0050]
In the cutting operation, first, the diameter expanding bit is pressed against the main body rod 34 in the state accompanied with the pressing of the diameter expanding bit 26 against the hole bottom of the drilling hole. Under the application of the rotational force in the direction, the lock means 58 of the joint unit is unlocked, thereby ensuring the free sliding state of the joint unit 38. When the outer tubular adapter 40 is rotated in the screwing direction in this state, the tubular adapter is screwed and separated from the outer casing 14 of the existing double pipe as shown in FIG.
[0051]
At this time, the joint unit 38 in the free slide state is extended under the movement of the main body rod 34 with respect to the slide rod 36, and by this extension, the screwing movement of the tubular adapter 40 from the outer casing 14 is ensured.
[0052]
That is, in this configuration, the outer casing 14 and the tubular adapter 40 that are not accompanied by the pulling up of the inner rod 12 can be easily separated from each other, and further, the outer casing and the double pipe swivel 22 can be easily separated.
[0053]
After the tubular adapter 40 is screwed and separated from the outer casing 14 as described above, the rotational drive mechanism 20 is applied while applying a rotational force in the reverse rotation direction from the joint unit 38 to the inner rod, that is, the diameter expanding bit 26. By retracting the double-tube swivel 22 under the slide of FIG. 2 (see FIG. 2), the tubular adapter 40 and the body rod 34 are further lifted as shown in FIG. After reaching, the inner rod 12 of the existing double pipe is pulled up from the outer casing 14 by a corresponding amount (see FIG. 8).
[0054]
In addition, since the diameter expansion bit 26 is reduced in diameter by the reverse rotation, when the inner rod 12 is pulled up while maintaining the reverse rotation state, the diameter expansion bit does not engage the outer casing 14 tip. The inner rod can be easily lifted.
[0055]
Then, in a state where the inner rod 12 protrudes from the outer casing 14 as shown in FIG. 8, a gripping means, for example, a single wrench 66 is hung on the notch 64 of the inner rod, and this inner rod is gripped. By rotating the joint unit 38, that is, the slide rod 36 with respect to the inner rod in the screwing direction, the slide rod, that is, the joint unit is separated from the inner rod as shown in FIG.
[0056]
In such a state where the auxiliary double pipe 42 is separated from the existing double pipe 16, for example, the next additional double pipe is added.
[0057]
It should be noted that the additional double pipe extension work may be performed as a substantially reverse procedure of the above-described disconnection work, and therefore detailed description thereof will be omitted here.
[0058]
As described above, in the double pipe drilling device 10 of the present invention, the extendable joint unit 38 is interposed between the inner rod 12 and the double pipe swivel 22 of the existing double pipe. It is possible to separate the outer casing 14 and the outer tubular adapter 40 from each other without pulling up the inner rod, that is, separation between the outer casing and the double pipe swivel.
[0059]
That is, when the outer casing 14 and the double tube swivel 22 are separated, the diameter of the diameter-expanding bit 26 disposed at the tip of the fluid hammer 24 is not limited. Therefore, it is possible to easily ensure the screwing operation without the engagement of the diameter expanding bit.
[0060]
Then, after the separation between the outer casing 14 and the double pipe swivel 22, it is sufficient to pull up the inner rod 12 while confirming whether or not the outer casing 14 and the double pipe swivel 22 can be pulled up. Therefore, the reliability of the work can be easily ensured.
[0061]
In other words, according to the present invention, when the outer casing 14 and the double pipe swivel 22 are separated, the safety of the diameter expanding bit 26 and the outer casing tip is ensured, and the inner rod 12 is lifted with respect to the outer casing. It is easy to improve workability.
[0062]
In the present invention, since the extendable joint unit 38 can be restricted from being expanded and contracted under the lock means 58, smooth and reliable forward and backward movement of the inner rod 12 with respect to the outer casing 14 can be easily ensured. Also in this respect, the workability is improved.
[0063]
Here, in this embodiment described above, the locking means 58 is embodied as a combination of the circumferential protrusion 60 and the fitting recess 62. However, since it is sufficient that the expansion and contraction between the main body rod 34 and the slide rod 36 can be restricted, the present invention is not limited to this. For example, a configuration having a separate lock pin 66 as shown in FIG. The locking means 158 may be provided.
[0064]
As can be seen from FIG. 11 in addition to FIG. 10, the locking means 158 is provided on the outer surface of the tubular adapter 40, the through hole 68 in the direction orthogonal to the axis, and the peripheral surface of the slide rod 36. The lock groove 70 in the circumferential direction and the lock pin 66 inserted into and engaged with the lock groove of the slide rod by passing through the through hole from the outside of the tubular adapter are combined into the lock groove. By inserting the lock pin into the through hole with the insertion and engagement, the slide rod can be regulated with respect to the tubular adapter.
[0065]
As shown in FIG. 10, after inserting the lock pin 66 into the through hole 68, a locking pin 72 for preventing the dropout is removably engaged with the insertion hole 66a at the extended end, thereby removing the tubular adapter. It is possible to easily prevent the lock pin from dropping from 40.
[0066]
The timing of locking and unlocking by the locking unit 158 is the same as the locking and unlocking of the locking unit 58 in the above-described embodiment. That is, when the inner rod 12 is inserted into the outer casing 14, the lock is achieved by inserting the lock pin 66, and when the outer casing is separated from the double pipe swivel 22, the lock is released by removing the lock pin. Each is selected.
[0067]
When the locking means 158 having the lock pin 66 is used, the separation work between the outer casing and the double pipe swivel 22 is the same as that described above except for the unlocking by removing the lock pin from the through hole 68. Since it is not different from the form, the description for this separation work is based on the above description, and the description here is omitted.
[0068]
According to the locking means 158, the locked state and unlocked state of the joint unit 38 can be visually confirmed with or without the lock pin 66, so that the state can be clarified. Therefore, the workability and work reliability are further improved.
[0069]
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.
[0070]
【The invention's effect】
As described above, according to the double-pipe drilling device according to the present invention, the extendable joint unit is interposed between the inner rod of the existing double-pipe and the double-pipe swivel. It is possible to separate the outer casing and the double-pipe swivel without raising them. In other words, when the outer casing and the double-tube swivel are separated from each other, the diameter-expanding bit of the diameter-expanding bit disposed at the tip of the fluid hammer is not limited. Therefore, it is possible to easily secure a screwing operation without any engagement.
[0071]
Then, after the separation between the outer casing and the double pipe swivel, it is sufficient to pull up the inner rod while confirming whether or not the outer casing can be lifted. Therefore, the reliability of the work can be easily ensured.
[0072]
Therefore, according to the present invention, when separating the outer casing and the double pipe swivel, it is possible to ensure the safety of the diameter expanding bit and the tip of the outer casing, and to improve the workability of the operation of lifting the inner rod with respect to the outer casing. It is easy to take off.
[0073]
In the present invention, since the extendable joint unit can be restricted from being expanded and contracted under the locking means, smooth and reliable forward and backward movement of the inner rod with respect to the outer casing can be easily ensured. However, the workability is improved.
[0074]
Further, if the rotation restriction between the main body rod and the slide rod is performed by the combination of the spline shaft and the spline groove, the configuration can be reliably prevented from becoming complicated.
[0075]
Furthermore, if the combination of the circumferential protrusion of the spline shaft and the fitting recess of the spline groove is used as a locking means, the configuration can be sufficiently simplified in this respect.
[0076]
If the locking means has a separate lock pin, the locked state and unlocked state of the joint unit can be visually confirmed, so that the state can be clarified. Therefore, the workability and work reliability are further improved.
[0077]
In addition, if a sealing member that seals the periphery of the slide rod is fixedly disposed at the end of the double tube swivel side, fluid leakage from around the slide rod can be reliably prevented in the main body rod. Become.
[0078]
Furthermore, if the seal member is a combination of a substantially cylindrical main body that can be mounted on the slide rod and an O-ring mounted around the main body, the reliable sealing can be achieved without complicating the configuration. Can be secured easily.
[Brief description of the drawings]
FIG. 1 is a partially cutaway schematic side view of a double pipe drilling device according to the present invention.
FIG. 2 is a schematic side view of a drilling device main body in the double-pipe drilling device.
FIG. 3 is a schematic cross-sectional view of a joint rod in a double pipe drilling device.
FIG. 4 is a schematic exploded perspective view of a joint rod with a part broken away.
FIG. 5 is a work diagram illustrating a separation work procedure in the double pipe drilling device.
FIG. 6 is a work diagram illustrating a separation work procedure in the double pipe drilling device.
FIG. 7 is a work diagram showing a detachment work procedure in the double pipe drilling device.
FIG. 8 is a work diagram illustrating a separation work procedure in the double pipe drilling device.
FIG. 9 is a work diagram showing a detachment work procedure in the double pipe drilling device.
FIG. 10 is a partially exploded perspective view showing a modification of a part of the double pipe drilling device of the present invention.
FIG. 11 is a partial plan view with partial breakage in a modification of the present invention.
[Explanation of symbols]
10 Double pipe drilling equipment
12 Inner rod
14 Outer rod
16 Existing double pipe
22 Double tube swivel
24 Fluid Hammer
26 Expanding bit
34 Body rod
36 Slide rod
38 Joint unit
40 Tubular adapter
42 Supplementary double pipe
50 adapter
51 Sealing member
58 Locking means
60 Circumferential protrusion
62 Fitting recess
158 Connecting jig (locking means)

Claims (6)

The existing double pipe, which is a combination of a hollow inner rod and an outer casing that surrounds and surrounds the inner rod, is a double pipe that serves as a fluid supply port into the inner rod with respect to the rotation drive mechanism of the drilling device main body. A fluid hammer having a diameter expansion bit that is connected via a swivel and whose diameter is increased or decreased depending on the direction of rotation is disposed in the outer casing under the support of an inner rod. It is a double pipe drilling device with an expanded bit method,
An inner joint unit having a hollow main body rod having a through passage, and a slide rod partially loosely inserted in the main body rod with rotation restriction; An auxiliary double pipe as a combination of an outer tubular adapter capable of separating and enclosing the joint unit corresponding to the shortened length of the joint unit between the double pipe swivel and the existing double pipe, Interposed between the inner rod and the threaded connection between the opposing threaded parts to the outer casing and the double pipe swivel,
Under the lock of the lock means that makes it impossible to expand and contract between the main body rod and slide rod under the engagement, it is possible to regulate the extension of the joint unit from its shortened state, and the lock means is unlocked This makes it possible to guarantee the extension of the joint unit. Among the slide rods of the joint unit, the thin shaft portion on the double tube swivel side that is loosely inserted into the main body rod is a spline shaft that has radial linear protrusions extending in the axial direction on its peripheral surface. 2. An adapter having a spline groove corresponding to the spline shaft on the inner peripheral surface thereof is fixedly disposed at the inner rod side end of the main body rod, thereby restricting the rotation of the slide rod relative to the main body rod. The double pipe drilling device as described. The slide rod spline shaft is formed with a circumferential protrusion partially protruding in one circumferential direction, and the adapter rod of the main body rod can be fitted into the spline shaft circumferential protrusion. Continuously in the spline groove,
The combination of the circumferential protrusion and the fitting recess is used as a locking means, and the locking direction of the locking means is matched with the diameter rotation direction of the diameter expanding bit by matching the locking direction of the diameter expanding bit. The double pipe drilling device according to claim 2, wherein unlocking can be ensured. A through-hole in a direction orthogonal to the axis provided in the outer tubular adapter;
A circumferential locking groove provided on the peripheral surface of the slide rod;
A lock pin inserted into and engaged with the lock groove of the slide rod by passing through the through hole from the outside of the tubular adapter;
The double pipe drilling device according to claim 1 or 2, wherein a combination of the above is used as a locking means. Claims made possible to prevent leakage of fluid from around the slide rod in the body rod by fixedly arranging a seal member for sealing the periphery of the slide rod at the end of the double tube swivel side. The double pipe drilling device according to any one of 1 to 4. The double-pipe drilling device according to claim 5, wherein the seal member is formed as a combination of a substantially cylindrical main body that can be mounted on the slide rod; and an O-ring mounted around the main body.

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