JP2000291359A - Method and device for boring large calibre hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhaust dug slime smoothly in a large calibre hole boring. SOLUTION: When a natural ground is reinforced by burying a steel outer tube 24, a thrust, rotation, and hammering are transmitted to an inner tube rod 22 and a boring bit 20 through a shank rod 38 in order to dig the natural ground and form a bored hole. In this case, cooling medium A is supplied to a medium supply passage 28 through a supply port 34, and the medium A is injected from the boring bit 20 to the natural ground. The dug powder is mixed with the cooling medium A to form digging slime B, and the digging slime B is exhausted to the outside from an exhaust port 36 through an exhaust passage 30. In the exhaust process of the digging slime B, the rotating force is transmitted to a soil removing sleeve 58 and the soil removing sleeve 58 is drivingly rotated in the same direction as the inner tube rod 22. When the sleeve 58 is drivingly rotated the digging slime B is moved to a swivel 32 side in the exhaust passage 30 according to the rotation of a screw vane 56.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drilling large-diameter holes, and more particularly to a technique for discharging excavated slime when excavating large-diameter holes.

[0002]

2. Description of the Related Art In tunnel excavation work on a ground with many cracks and slip surfaces, a sedimentary ground, a low-strength soft rock, or an expansive ground, it is necessary to secure the stability of the ground before excavation. There is. As one of the construction methods for stabilizing the ground having such properties, a long steel pipe front receiving construction method is known.

[0005] FIG. 5 shows a typical construction state of a ground drilling method in a long steel pipe tip receiving method. In the drilling method shown in FIG. 1, an inner pipe rod 2 having a drill bit 1 attached to a tip end, an outer pipe 3 accommodating the inner pipe rod 2 therein, and a thrust and rotation are applied to the drill bit 1. A drifter 4 for applying force and impact force is used.

[0004] The inner pipe rod 2 is a rod body having a screw engraved on both ends, and is successively added and connected via a coupling as the excavation progresses.
A medium supply passage 5 for supplying a cooling medium a is formed to pass therethrough.

[0005] The outer pipe 3 is a hollow cylindrical steel pipe having threads cut at both ends. Like the inner pipe rod 2, the ends are mutually screwed together as the excavation progresses. The gap between the inner pipe rod 2 and the outer peripheral surface of the inner pipe rod 2 inserted therein constitutes a discharge passage 6 for excavation slime b generated with excavation.

A swivel 7 is mounted on the rear end side of the outer pipe 3. The swivel 7 has a supply port 8 for the cooling medium a communicating with the medium supply passage 5 of the inner pipe rod 2 and a discharge port 6. An outlet 9 for the excavating slime b communicating with the slime b is provided.

The drifter 4 is connected to the inner pipe rod 2 via a shank rod 10. Drifter 4
Is supported by a guide cell 12 via a guide shoe 11 provided at the lower end so as to be movable back and forth.

At the distal end of the guide cell 12, a sentizer 13 for positioning and supporting the outer tube 3 is provided.
When the steel pipe is buried to reinforce the ground c, by driving the drifter 4, the thrust, the rotational force and the impact force are reduced.
It is transmitted to the inner pipe rod 2 and the drill bit 1 via the shank rod 10, whereby the ground c is excavated and drilled d.
Is formed.

At this time, a cooling medium a selected from drilling water or air is supplied to the medium supply passage 5 through the supply port 8, and the cooling medium a is transferred from the drill bit 1 to the ground c. Injected toward.

The cutting powder drilled by the drill bit 1 is:
Mixed with the cooling medium a to form drilling slime b,
The excavation slime b is discharged from the discharge port 9 to the outside via the discharge passage 6.

Since the thrust and the impact of the drifter 4 are applied to the outer pipe 3 from the rear end side in the drilled hole d excavated by the drill bit 1, the outer pipe 3 is drilled by the pushing method. Inserted in d.

However, in such a conventional drilling method, the diameter of the drilled hole is particularly large, for example, when the diameter is 6 mm.
When forming a large-diameter hole of 5 mm or more, there was a technical problem described below.

[0013]

That is, the diameter is 65.
In the case of forming a drilled hole having a large diameter of not less than mm, the amount of drilling powder drilled by the drilling bit 1 becomes very large, and therefore, the amount of drilling slime b to be discharged naturally becomes large.

However, if a large amount of drilling slime b is to be discharged by drilling water or air, a large amount of drilling water or air is required. When a large amount of air is used, a large amount of dust is generated, and the working environment is similarly deteriorated. On the other hand, the double-pipe drilling method using the inner pipe rod 2 and the outer pipe 3 as shown in FIG. 5 is a method adopted when the ground c to be excavated is relatively soft. In the drilling method, when the outer pipe 3 is buried in the ground c by a predetermined length, the inner pipe rod 2 is pulled out. At this time, the outer pipe 3 is contained in the excavation slime b in the discharge passage 6. If the dust remains, it becomes very difficult to pull out the inner tube rod 2.

[0015] The problem associated with the residue of the bobbin dust can be avoided by, for example, increasing the supply pressure of drilling water or air.
Another problem occurs in that the ground c is cracked, the slip surface is loosened, and the ground c is damaged.

As a solution to such a problem, for example, as proposed by the present applicant in Japanese Patent No. 2666600, there is a drilling method using a bubble entrained in compressed air as a cooling medium a. .

In the drilling method according to this patent, a foaming agent solution and compressed air are pressure-fed to the tip of the drill bit 1 as a gas-liquid two-phase fluid, and turbulence occurs near the injection port at the tip of the drill bit 1. By causing the flow, the gas-liquid two-phase fluid is foamed to generate air bubbles, and the air bubbles are mixed with the cutting powder excavated by the drill bit 1 and discharged to the outside as excavation slime.

Since the air bubbles injected from the drill bit 1 as the cooling medium a have a high viscosity, they hardly penetrate into cracks and the like, do not damage the ground, and have a drilling slime mixed with air bubbles. The fluidity is increased, and it becomes possible to easily discharge the cutting powder from the inside of the hole d. However, even in the drilling method according to this patent, when excavating a large-diameter drilling hole, if the supply amount of bubbles is insufficient, the cutting powder contained in the drilling slime b remains in the discharge passage 6. However, there is a problem that it is very difficult to pull out the inner pipe rod 2.

In addition, when the ground c to be drilled is under special conditions, for example, slaking is caused by water on a Shirasu plateau that collapses when given water or bubbles, or a serpentinite ground containing montmorillonite minerals. In some cases, the amount of water and bubbles used must be extremely limited. In such a drilling of the ground, the drilling slime b contained in the discharge passage 6 is in the same manner as described above. Powder remains and the inner pipe rod 2
There is a problem that it becomes very difficult to pull out the garbage.

The present invention has been made in view of such conventional problems, and has as its object the purpose of the present invention even when the supply amount of bubbles is insufficient or when it is necessary to restrict the supply. Another object of the present invention is to provide a large-diameter drilling method in which cuttings in excavation slime do not remain in a discharge passage.

[0021]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an inner pipe rod equipped with a drill bit for drilling a large bore having a diameter of 65 mm or more, and an inner pipe rod including the drill bit. Using an outer pipe housed inside, drilling a drilling while applying thrust, rotation and impact to the drilling bit, provided inside the inner pipe rod when drilling this drilling While supplying a cooling medium from the medium supply passage to the drill bit, the excavation slime accompanying the excavation was discharged to the outside via the slime discharge passage provided between the inner pipe rod and the outer pipe, and the excavation was performed. In the drilling method of inserting the outer pipe into the drilled hole, a discharging sleeve provided with a screw blade on an outer peripheral side is fitted on an outer circumference of the inner pipe rod, and the discharging sleeve is connected to the inner pipe rod. By rotating with It was to move the drilling slime to the rear. In the large-diameter drilling method configured as described above, a discharging sleeve provided with a screw blade on the outer peripheral side is fitted on the outer circumference of the inner pipe rod, and the discharging sleeve is driven to rotate together with the inner pipe rod. Since the excavation slime is moved backward, even if the supply of air bubbles is insufficient or the supply needs to be restricted, even if the fluidity of the excavation slime is reduced, the dust in the excavation slime may be discharged. It will not remain inside. The earth removal sleeve is independent of the inner pipe rod and can be attached and detached according to the drilling mode. According to this configuration, if the cooling medium such as air bubbles is sufficiently supplied to the excavation slime, or if it can be supplied, the discharging sleeve may be detached,
Either one can be selected according to the nature of the ground, so the degree of freedom in construction increases. A rotational force transmitting portion having a polygonal structure that is fitted between the discharging sleeve and the inner pipe rod in a state where mutual movement in the axial direction is allowed may be provided. According to this configuration, the screw blade that is vulnerable to impact can be effectively protected. A buffer sleeve for reducing impact force can be interposed between the earth discharging sleeve and the inner pipe rod. According to this configuration, the screw blade that is vulnerable to impact can be more effectively protected. Further, the present invention includes an inner pipe rod equipped with a drill bit for drilling a large-diameter drill hole, and an outer pipe for housing the inner pipe rod therein. A drilling hole is excavated while applying a striking force. When excavating the drilling hole, a cooling medium is supplied to the drilling bit from a medium supply passage provided inside the inner pipe rod, and the inner pipe rod is excavated. In a drilling device that discharges excavation slime associated with excavation through a slime discharge passage provided between the outer tube and the outer tube, and inserts the outer tube into the drilled hole, a screw is provided on an outer peripheral side. A blade is provided, and a discharging sleeve detachably fitted to the outer periphery of the inner pipe rod is provided, and the discharging sleeve is driven to rotate together with the inner pipe rod. According to the drilling device configured as described above, the drilling slime is moved backward by rotating and driving the discharging sleeve together with the inner pipe rod.
When the supply amount of the air bubbles is insufficient or when the supply needs to be restricted, even if the fluidity of the excavation slime is reduced, the dust in the excavation slime does not remain in the discharge passage.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 show an embodiment of a large-diameter drilling method and a drilling apparatus used in the method according to the present invention.

In the drilling method shown in FIG. 1, an inner pipe rod 22 having a drill bit 20 attached to a tip end thereof, an outer pipe 24 accommodating the inner pipe rod 22 therein, and a drill bit 20 are provided.
And a drifter 26 that applies a thrust, a rotational force, and a striking force to the motor.

The inner pipe rod 22 is a rod body having a screw engraved on both ends, and is successively added and connected via a coupling 23 as the excavation progresses. Supply path 2 for supplying cooling medium A to
8 are formed through.

The outer pipe 24 is a hollow cylindrical steel pipe having threads cut at both ends. Like the inner pipe rod 22, the outer pipe 24 has its ends screwed together with the progress of excavation. Between the outer peripheral surface of the inner pipe rod 22 and the excavation slime B generated with the excavation.
Discharge passage 30.

At the rear ends of the inner pipe rod 22 and the outer pipe 24,
A swivel 32 is attached to the swivel 32. The swivel 32 has a supply port 34 for the cooling medium A communicating with the medium supply passage 28 of the inner pipe rod 22, and a drilling slime B communicating with the discharge passage 30.
Outlet 36 is provided.

The drifter 26 is connected to the inner pipe rod 22 and the outer pipe 2 via a shank rod 38 and a connecting rod 39.
4. In the case of the present embodiment, as described later, the outer tube 24 is inserted into the hole D by a forward pulling method, so that it is not necessary to connect the outer tube 24 to the drifter 26.

The drifter 26 is supported by a guide cell 42 via a guide shoe 40 provided at the lower end so as to be movable back and forth.

At the front end side and intermediate position of the guide cell 42,
A pair of sent risers 46 for positioning and supporting the outer tube 24
Is provided. FIG. 3 is an enlarged view of the vicinity of the drill bit 20 shown in FIGS. 1 and 2, and the drill bit 20 of the present embodiment is a ring lost bit 20a.
And the inner bit 20b, which is constituted by the inner bit 20b and the inner bit 20b fitted to the ring lost bit 20a.
b is inserted inside the casing shoe 46.

The distal end of the inner tube rod 22 is screwed to the rear end of the inner bit 20b, and the outer circumferential surface thereof has a concave groove 20c divided along the circumferential direction.
Are provided along the axial direction of the inner bit 20b.

The casing shoe 46 is a hollow cylindrical body having both ends opened. The front end of the outer tube 24 is fitted and connected to the rear end of the casing shoe 46, and the rear end of the ring lost bit 20a is connected to the front end. The outer peripheral part is fitted.

The medium supply passage 28 provided inside the inner pipe rod 22 extends through the inner bit 20b in the axial direction and opens at the tip of the inner bit 20b.

The distal end of the concave groove 20c provided on the outer periphery of the inner bit 20b opens at the outer peripheral edge of the distal end of the inner bit 20b, and the rear end of the concave groove 20c is connected to the inner pipe rod 22.
And the discharge passage 30 of the excavation slime B provided between the outer peripheral surface of the outer pipe 24 and the inner peripheral surface of the outer pipe 24.

A power transmitting portion 48 for thrust and impact applied from the drifter 26 is provided between the inner bit 20b and the casing shoe 46.
The power transmission section 48 of the present embodiment includes a step section 50 provided on the casing shoe 46 and a convex section 52 provided on the inner bit 20b.

The step portion 50 is provided substantially at the center of the casing shoe 46 in the axial direction, and is provided on the inner peripheral surface thereof.
The convex portion 52 is formed so as to protrude from the outer periphery of the rear end side of the inner bit 20b, is divided by the concave groove 20c, and
And the convex portion 52 are in contact with each other.

When a thrust and a striking force are applied from the drifter 26 in a state where the step portion 50 and the convex portion 52 are in contact with each other,
Through these abutments, this thrust and impact force are:
The outer tube 24 is also transmitted to the outer tube 24 via the casing shoe 46, so that the outer tube 24 can be inserted into the hole D by a front pulling method.

On the other hand, a slime B discharging section 54 is provided in the discharge passage 30 for the excavated slime B. The discharging portion 54 is provided with screw blades 5 formed around the outer peripheral surface.
And a hollow cylindrical discharging sleeve 5 having both ends opened.
8 and a hollow cylindrical buffer sleeve 60 made of hard rubber or the like.

The discharging sleeve 58 has substantially the same length as the inner pipe rod 22 and is fitted around its outer periphery in such a manner that it can be moved in the axial direction. An enlarged diameter portion 62 through which the coupling 22 of FIG. 22 can be inserted is provided.

A thrust ring 64 having a predetermined thickness is formed on the outer periphery of the coupling 23 provided on the distal end side of the inner pipe rod 22 so as to protrude therefrom. Expanded portion 6 of soil sleeve 58
2, a buffer sleeve 62 is interposed.

The middle portion of the earth discharging sleeve 58 is configured such that the expanded diameter portion 62 is inserted from both sides of the coupling 23 with the buffer sleeve 62 inserted around the coupling 23 of the inner pipe rod 22. It is fitted.

In this case, by forming the outer shape of the coupling 23 into a polygon and the inner peripheral surface of the enlarged diameter portion 62 into a shape into which the polygon can be fitted, it is possible to move the coupling 23 in the axial direction. Only the rotational force is discharged from the inner pipe rod 22 to the discharging sleeve 58.
Is provided.

The rotational force transmitting portion 66 having such a polygonal fitting structure is also provided on the rear end side of the discharging sleeve 58. The rear end side rotational force transmitting portion 66 is configured by mounting a polygonal nut 67 that can be fitted to the enlarged diameter portion 62 on the outer periphery of the inner pipe rod 22.

A thrust ring 68 is fitted and fixed to the outer periphery of the distal end of the connecting rod 39 connected to the inner pipe rod 22 at the rear end side of the earth discharging sleeve 58, and a cushion is provided between the thrust ring 68 and the enlarged diameter portion 62. The sleeve 60 is interposed.

When the outer pipe 24 made of steel pipe is buried to reinforce the ground C, the thrust, the rotational force and the striking force are reduced by driving the drifter 26 via the shank rod 38. And the drill bit 20, whereby the ground C is excavated to form the drill hole D.

At this time, a cooling medium A selected from bubbles, drilling water, and air mixed with the compressed air is supplied to the medium supply passage 28 through the supply port 34, and the cooling medium A
Is injected from the drill bit 20 toward the ground C.

The cuttings drilled by the drill bit 20 are mixed with the cooling medium A to form drilling slime B. The drilling slime B is discharged to the outside through the discharge passage 36 through the discharge passage 30.

In the process of discharging the excavation slime B,
In the case of the present embodiment, since the rotational force of the drifter 26 is transmitted to each of the earth discharging sleeves 58 via the rotational force transmitting part 66, the earth discharging sleeve 58 rotates in the same direction as the inner pipe rod 22. Driven.

When the discharging sleeve 58 is driven to rotate, the screw blade 56 is provided on the outer periphery thereof.
The discharge passage 30 is moved toward the swivel 32, that is, toward the rear side.

On the other hand, since the thrust and the impact of the drifter 26 are applied to the outer pipe 24 from the front end side in the drilled hole D excavated by the drill bit 20, the outer pipe 24 is drawn by the forward pulling method. Is inserted into the hole D.

By continuing such an operation, when the outer pipe 24 is buried in the ground C having a predetermined length, the operation is stopped, the inner pipe rod 22 is collected together with the inner bit 20b, and the hole is drilled. End the process.

According to the drilling method and the drilling device performed as described above, the excavation sleeve 58 is driven to rotate together with the inner pipe rod 22 so that the excavation slime is formed.
Since B is moved to the swivel 32 side, when the supply amount of air bubbles is insufficient or when the supply needs to be restricted, even if the fluidity of the excavation slime B decreases, It does not remain in the discharge passage 30.

Further, in the case of the present embodiment, the earth discharging sleeve 58 is independent of the inner pipe rod 22 and can be attached and detached according to the drilling mode. If the medium A can be supplied sufficiently,
Alternatively, when the cooling A can be sufficiently supplied, the discharging sleeve 58 may be detached, and according to the properties of the ground,
Since either one can be selected, the degree of freedom of construction increases.

In the case of the present embodiment, a polygonal structure rotational force transmitting portion which is fitted between the earth discharging sleeve 58 and the inner pipe rod 22 in a state where mutual movement in the axial direction is allowed. 6
Since the screw blades 6 are provided, the screw blades 56 that are vulnerable to impact can be effectively protected.

Further, in the case of the present embodiment, since the cushioning sleeve 60 for alleviating the impact force is interposed between the earth discharging sleeve 58 and the inner pipe rod 22, the screw blade which is vulnerable to impact is provided. 56 can be protected more effectively.

[0055]

As described above in detail in the embodiments,
According to the large diameter drilling method and drilling device according to the present invention, when the supply of the cooling medium such as air bubbles is insufficient,
Even when the supply is restricted, the excavation slime can be discharged smoothly.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a construction state showing one embodiment of a large diameter drilling method according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is an enlarged view of a main part of FIG. 2;

FIG. 5 is an explanatory view of a construction state showing an example of a conventional drilling method.

[Explanation of symbols]

 Reference Signs List 20 drilling bit 22 inner pipe rod 24 outer pipe 26 drifter 28 medium supply passage 30 discharge passage 32 swivel 54 discharging section 56 screw blade 58 discharging sleeve 60 buffer sleeve A cooling medium B drilling slime C ground pile D drilling

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masatomo Nakajima 2-15-2 Konan, Minato-ku, Tokyo Obayashi Corporation Tokyo Head Office (72) Inventor Tomi Matsumoto 486 F-term, Kamizuma, Sagamihara City, Kanagawa Prefecture (Reference) 2D029 DA02

Claims (5)

[Claims] An internal pipe rod equipped with a drill bit for drilling a large-diameter drill hole, and an outer pipe accommodating the inner pipe rod therein. When drilling a hole while applying force, when drilling the hole, while supplying a cooling medium to the drill bit from a medium supply passage provided inside the inner pipe rod, the inner pipe rod and In a drilling method of discharging excavation slime associated with excavation through a slime discharge passage provided between the inner pipe rod and the inner pipe rod, The excavation slime is moved rearward by fitting an earthing sleeve provided with a screw blade on the outer periphery on the outer periphery and rotating the earthing sleeve together with the inner pipe rod. Drilling method. 2. The large-diameter hole drilling method according to claim 1, wherein the earth discharging sleeve is independent of the inner pipe rod and is attached and detached according to a drilling mode. 3. A polygonal torque transmitting portion is provided between the earthing sleeve and the inner pipe rod so as to be fitted to each other in a state where they are allowed to move in the axial direction. The large-diameter drilling method according to claim 1 or 2. 4. The large-diameter cutting machine according to claim 1, wherein a buffer sleeve for reducing an impact force is interposed between the earth discharging sleeve and the inner pipe rod. Hole method. 5. An inner pipe rod provided with a drill bit for drilling a large-diameter drill hole, and an outer pipe accommodating the inner pipe rod therein, wherein the drill bit has a thrust, a rotational force, and an impact. When drilling a hole while applying force, when drilling the hole, while supplying a cooling medium to the drill bit from a medium supply passage provided inside the inner pipe rod, the inner pipe rod and A drilling device that discharges excavation slime associated with excavation through a slime discharge passage provided between the outer tube and the outer tube, and inserts the outer tube into the drilled hole. And a drilling sleeve detachably fitted to the outer periphery of the inner pipe rod, and the drilling sleeve is driven to rotate together with the inner pipe rod.