WO2006025713A1

WO2006025713A1 - A drilling apparatus having in-line extending wings and driving method thereof

Info

Publication number: WO2006025713A1
Application number: PCT/KR2005/002918
Authority: WO
Inventors: Byung-Duk Lim
Original assignee: Byung-Duk Lim
Priority date: 2004-09-03
Filing date: 2005-09-02
Publication date: 2006-03-09
Also published as: KR100685386B1; CN101010481A; EP1797274B1; JP2008511773A; HK1157424A1; EP1797274A1; IL181643A0; CA2578352A1; CN102174876A; IL181643A; CA2578352C; NO20071804L; NO333795B1; US7681671B2; JP4319236B2; CN102174876B; AU2005280737A1; US20090188719A1; AU2005280737B2; NZ554081A

Abstract

The present invention relates to a borehole drilling apparatus with in-line extending wings and driving method thereof. The drilling apparatus comprises a guide device rotating while moving upwardly and downwardly in a casing to fit into aborehole, extending wings for exterκling the diameter of adriUedhole, arκiapUotbitinstelledatalowerportionofthe guide deviceto strike the bottom of the borehole, wherein spiral projections formed at a lower surface of tiie guide device slidably engage with guide grooves formed at a side of the extending wings to each other, and a window is formed at a side of Hie pilot bit for advancing and retracting the extending wings so that they can spread and return linearly from the center of the pilot bit

Description

ADRILUNG APPARATUS HAVING IN-LINE EXTENDING WINGS AND DRIVING

MEIHODTHEREOF

Technical Field

The present invention relates to a borehole drilling apparatus having in-line extending wings and driving method thereof, in particular to a borehole drilling apparatus havirig ^

which comprises a guide device operated by high pressure air, extending wings and a pilot bit, the extending wings being configured to advance and retract in an in-line manner so as to extend the diameter of a borehole so that sludge can be prevented ftom being accumulated in the space to which the extending wings return, and a driving method thereof.

Background Art

Ih general, hammer bit equipment used in drilling a borehole includes a rotation apparatus, a striking apparatus and a drilling apparatus. The present invention is directed to the drilling apparatus located at the lowest portion of the hammer bit equipments. The drilling apparatus can be divided into an eccentric type, an extending type and a blade extending type depending on means for extending the diameter of the borehole, for instance, the structure of a reamer, extending blades or arms.

As disclosed in US Patent No.4, 770, 259 (Published on Sep. 13, 1988), the eccentric type drilling apparatus includes a drill string and a cutting device connected to a lower end portion of the drill string. Further, the cutting device consists of an intermediate portion rotating within the drill string, and

an outer surface. Also, a reamer is installed in the intermediate portion so that it is offset with regard to the center axis. Accordingly, the reamer extends the diameter of the borehole by eccentric rotation in the eccentric type drilling apparatus.

In addition, as shown in Japanese Patent Laid-Open Publication No.2710192(pύblished on Nov. 29, 1994), the extending type drilling apparatus comprises a device driven by means of an air pump, a bit device installed at a distal end of the device, and an extending blade installed between Ihe

device and the bit device. The extending blade is secured at an upper end to the device by means of a pin so that it can move angularly in the vertical direction, and the upper end portion of the bit device is

formed to have an inclined surface. Therefore, the lower end portion of Hie extending blade is

configured to diverge along the inclined surface of Hie bit device when Hie device and the bit device come close to each other.

Further, as shown in US. Patent No.5, 787,999(issued on Aug.4, 1998), the blade extending type drilling apparatus includes a driver, under-reamer arms, and a pilot bit, in which a plurality of arms are constructed to project and retract while rotating fiom the center of the pilot bit to the inclined direction by means of a rotation force of the driver.

However, with regard to the eccentric type drilling apparatus, it is impossible to carry out rapid drilling work as the reamer rotates eccentrically, and there is a problem in that connection portion of the intermediate portion is liable to be damaged easily under high load. Also, with regard to the extending type drilling apparatus, it is impossible to use it under high load as tiie extending blade is extended with its angular movement to the longitudinal direction, and the fixing pin is apt to be damaged easily.

Further, in contrast to the eccentric or extending type drilling apparatus, although the blade extending type drilling apparatus can be used for high load drilling apparatus, there is a problem in that the contact portion between the arms and the pilot bit is susceptible to serious abrasion because the rotation force of Hie driver should spread the arms forcibly and rotate even Hie pilot bit via the arms at the same time, and the securing pin for fixing the arms are damaged frequently. Additionally, when the arms return to flieir original positions after the completion of the drilling work, sludge is liable to be

jammed in the space where Hie arms return to thereby hinder Hie arms' return to their original positions,

so that it becomes somewhat difficult to retract the drilling apparatus from the casing to fit into the

borehole. Disclosure of Invention

Technical Problem

The present invention has been made to solve the above-mentioned problems occurring in the conventional striking type borehole drilling apparatus, and it is an object of the present invention to provide a borehole drilling apparatus of an improved structure, in which it is possible to perform a drilling work under a high load and at a high speed, it is easy to spread arκl return Ihe extending vvings, the working efficiency is excellent as the sludge is not accumulated in the space where the extending wings return, and it is possible to significantly reduce the maintenance and repair costs.

Technical Solution

To accomplish the above object, according to one aspect of the present invention, there is provided a borehole drilling apparatus and driving method thereof, wherein the borehole drilling apparatus comprises a guide device rotating with moving up and down in a casing to fit into the borehole, extending wings for extending the diameters of the drilled holes, and a pilot bit installed at a lower portion of the guide device to strike Hie bottom of Ihe borehole, wherein spiral projections formed at a lower surface of the guide device slidably engage with guide grooves formed at sides of the extending wings to each other, and a window is formed at a side of the pilot bit for advancing and retracting the extending wings so that tiiey can spread and return linearly from the center of the pilot bit In the present invention, as described above, the term of "In-line" driving manner refers to a

manner in which the extending wings spread from each other linearly from the center of the pilot bit,

and Ihey return to come close to each other linearly.

Brief Description of Drawings Further objects and advantages of the present invention can be more fully understood from the

following detailed description taken in conjunction with the accompanying drawings in which:

FIG 1 is a cross-sectional view showing structure of a borehole drilling apparatus according to

the present invention,

πG2isaviewshowingstnαctιπeofagmdedeΛd∞ l(X)shovvninFIG l,

FIG 3 is a structural view showing extending wings 200 shown in FIG 1,

FIG 4A is a planar view showing the extending wings 200, and FIG 4B is a cross-sectional

view of the extending wings taken along the line S-S,

FIG 5 is a structural view showing a pilot bit 300 shown in Fig. 1 ,

FIG 6A is a planar view of the pilot bit 300, FIG 6B is a cross-sectional view of the pilot bit

taken along tiie line S-S, FIG 6C is a cross-sectional view of the pilot bit taken along the line S'-S',

FIG 7 is a view showing structure of a ring-type pin according to an embodiment of the

present invention,

FIGs. 8 and 9 are views showing installing structure of the securing pin 400 according to

another embodiment of the present invention,

FIGs. 10 and 11 are views explaining an in-line driving method of the present invention.

Best Mode for Carrying Out the Invention

The present invention will hereinafter be described in further detail with reference to the

preferred embodiments.

the present invention, FIG 2 is a view showing structure of a guide device 100 shown in FIG 1, FIG 3

is a structural view showing extending wings 200 shown in FIG 1, FIG 4A is a planar view showing

the extending wings 200, and FIG 4B is a cross-sectional view of the extending wings taken along the line S-S₅FIG 5 is a perspective view showing a pilot bit 300 shown in Fig. 1, and FIG 6Aisaplanar

view of the pilot bit 300, FIG 6B is a cross-sectional view of the pilot bit taken along the line S - S, FIG

6C is a cross-sectional view of the pilot bit taken along the line S' - S'.

As shown in FIG 1, the borehole drilling apparatus comprises a guide device 100 engaged

with a striking device (not shown), extending wings 200 installed at a lower portion of the guide device

100 to extend the diameter of the borehole, and a pilot bit 300 for drilling the ground while supporting

the extending wings 200. In an embodiment of the present invention, a ring-type pin 400 is constructed

as pin engaging means for engaging the guide device 100 with the pilot bit 300.

At first, as shown in FIG 2, the guide device 100 includes an upper shaft portion 120, a lower

shaft portion 130 which have a smaller diameter, and a piston portion 110 having a relatively larger

diameter than the upper and lower shaft portions. As shown in FIG 1 , the piston portion 110 is installed

within a casing 10 while maintaining a small gap there-between so 1rM it operates to stoike an upper end

of the a shoe 12 installed at a lower end of the casing 10 to thereby progress the casing 10 into the

borehole. A plurality of sludge discharging grooves 30 are formed on the outer c^umferential surface

of 1he piston portion 110 for discharging the sludge such as soils, pebbles, and the like produced during

the drilling process ftom the borehole. As shown in FIG 1 , an air hole 20 is formed along a center axis

of the piston portion 110 while passing through the piston portion 110, the upper shaft portion 120, and

the lower shaft portion 130 for supplying high pressure air along me longitudinal direction fiom Ihe

outside.

The upper shaft portion 120 is provided with shaft engaging grooves 121 formed on Hie outer

circumferential surface thereof for engaging with the striking device (not shown), which is an upper

structure of the drilling apparatus. Spiral projections 131 with curved surface are formed at the bottom

of the lower shaft portion 130, in which the diameter of the curved surface increases progressively fiom

the center, and a retaining protrusion 132 is formed on the outer circumference of the lower shaft portion 130. Also, a pin groove 133 is formed with which the ring-type pin 400 is engaged, along the

outer άrcuπiiereritial surface at justbelowthe piston portion 110, that is, an upper side of the lower shaft

portion 130.

The extending wings 200 are configured as shown in FIGs. 3 and 4, a guide groove 210 is

formed at the inside of the extending wings for engaging with the spiral projection 131 of the guide

device 100. Also, a stepped surface 220 is formed on the outside upper surface of the extending wing

200, and an inclined surface 230 is formed at a lower comer of the extending wings. Further, a plurality

of burton tips 40 made of special steel are driven into the inclined surface 230 to facilitate the drilling

work.

Meanwhile, as shown in FIGs.5 and 6, the pilot bit 300 is configured to be a cylindrical vessel

shape, and the lower shaft portion 130 of the guide device 100 and the extending wings 200 are

received in the pilot bit 300.

A rectangular-shaped window 310 for advancing and retracting Hie extending wing 200 is

formed at a side of Hie pilot bit 300, a retaining step 320 is formed inwardly from an inner

circumferential surface of the pilot bit to correspond to the retaining protrusion 132 of Hie guide device

100, and apin groove 330 is formed at aposition of the inner circumferential surface corresponding to a

pin groove 133 of the lower shaft portion 130. The pin groove 330 is communicatively connected with

the outside by a pin insertion hole 331. Also, an air hole 20 is formed at a lower surface of the pilot bit

300, and a plurality of sludge discharge grooves 30 are formed on the outer circumferential surface of

the pilot bit, and button tips 40 are driven into the lower surface of the pilot bit

FIG 7 shows structure of a ring-type pin 400 used in an embodiment of the present invention,

in which a plurality of arc-shaped pins are combined to form a circle. The ring-type pin 400 is fit into a

pin groove 133 formed at the outer circumferential surface of the lower shaft portion 130 of the guide

device 100, and a pin hole is formed by the pin groove 330 defined at the inner άrαmiferential surface of the pilot bit 300 to clamp Hie guide devjce 100 and the pilot bit 300. Ih this instance, each of Ihe arc-

shaped pins 410 are inserted into the pin hole respectively via the pin insertion hole 331 formed at the

pin groove 330 of the pilot bit 300. Apin support element 332 is inserted into the pin insertion hole 331

so that the arc-shaped pins 410 cannot be separated ftom the pin holes, and a bolt (not shown) is

engaged with a bolt hole 333 thereby to finish the clamping of the ring-type pin.

Meanwhile, FIG 8 and FIG 9 show different embodiments of the present invention, in which

the pin engagement means for clamping the guide device 100 and the pilot bit 300 includes a securing

pin 450 and a pin support rod 460 instead of the ring-type pin 400. FIG 8 shows longitudinal cross-

section of the extending wing 200 and the pilot bit 300, and FIG 9 shows cross-section taken along the

line S - S of FIG 8. As shown in the drawings, a pin insertion hole 350 is formed obliquely at a side of the pilot bit 300, and a pin retaining groove 360 is formed on the inner circumferential surface of the

pilot bit Also, a pin insertion hole 135 extending from the pin insertion hole 350 is formed obliquely at

the upper end of the lower shaft portion 130 of the guide device 100, and a pin receiving groove 136 is

formed within the pin insertion hole 135 to correspond to the pin retaining groove 360.

In order to assemble the borehole drilling apparatus according to the embodiment of the

present invention, the securing pin 450 is inserted into the pin receiving groove 136 of the guide device

100 at first, the guide device 100 is inserted into and engaged with the pilot bit 300, and then the pin

support rod 460 is forcibly pushed into the insertion hole 135 via the pin insertion hole 350. In this

instance, the pin support rod 460 pushes out the securing pin 450 so that it can be engaged with the pin

retaining groove 360 of the pilot bit 300 to thereby clamp the guide device 100 and the pilot bit 300 to

each oilier.

The in-line driving method of the borehole drilling apparatus of the present invention will now

be described below. FIG 10 and FIG 11 are views for explaining the driving principle of the drilling

apparatus in which two extending wings 200 are arranged linearly side by side according to an embodiment of the present invention.

At first, as shown in FIG 10, Hie guide device 100 (represented by thick solid line) rotates

clockwise to descend, with the pilot bit 300 in a state where the extending wings 200 (represented by

dotted thick line) are received within the pilot bit 300 (represented by thin solid line). When the lower

surface of the pilot bit 300 begins to strike a bottom surface of the borehole, rotation of the pilot bit 300

will be suppressed by the fictional force, and if the guide device 100 ∞πώiues to rotate at this state, the

spiral projections 131 (represented by a dotted portion) rotates along the guide groove 210 (represented

by reverse inclined lines) of the extending wing 200 in the direction enlarging radius to spread and

extend the extending wings 200 to the outside of the wing advancing arκl refracting window 310. Ih this

instance, the extending wing 200 is spread and extended linearly away from the center of the pilot bit

300 via the advancing and retracting window 310.

Then, as shown in FIG 11, when the retaining protrusion 132 of the guide device 100 contacts

the retaining step 320 (shown by inclined lines), spreading of the extending wings 200 is stopped, and

rotation force of the guide device 100 is transmitted to the pilot bit 300 itself to rotate the guide device

100, the extending wing 200 and the pilot bit 300 integrally to carry out the drilling work. Sludge such

as pebbles, sands and so on produced during the drilling work can be discharged via the sludge

discharge hole 30 by means of the compressed air supplied from the air hole 20.

Meanwhile, the return process of the extending wing 200 for the borehole begins with reverse

rotation and ascending of the guide device 100. In other words, as shown in FIG 11, when the guide

device 100 rotates counter-clockwise to ascend in a state where the extending wings 200 are spread, the

stepped surface 220 of the extending wings 200 contacts with the lower end of a shoe 12 in the casing

10, and the rotation of the extending wing 200 for the borehole is suppressed by the fictional force. At

this state, if the guide device continues to rotate reversely, the spiral projections 131 (represented by a

dotted portion) move along the guide groove 210 of the extending wing 200 in the direction decreasing T/KR2005/002918

the radius to thereby return the extending wings 200 into the window 310 of the pilot bit 300. In this

instance, the extending wings 200 return linearly to come close each other to the center of 1he pilot bit

300 via the advancing and retracting window 310 for the wings.

When the guide device 100 rotates reversely to contact with the retaining step 320 (shown by

inclined solid lines), as shown in FIG ll,tiieexterκlirigwirigs200finishrettim^

100, the extending wings 200 and the pilot bit 300 concurrently rotate to retract from the casing 10.

Ih the present invention, although it is preferable 1hat two extending wings 200 are installed at

bofli side as described in the above embodiment, three extending wings may be installed, if desired. In

case of installing three extending wings 200, the driving principle is basically tiie same as that of

installing two extending wings. However, the spiral projections 131 of the guide device 100 and the

wing advancing and retracting window 310 of 1he pilot bit 300 should be installed to be three so that

they can cope with three extending wings 200.

While the present invention has been described with reference to the preferred embodiments,

the present invention is not restricted by the embodiments. It is to be appreciated that those skilled in the

art can change or modify the embodiments without departing from the scope and spirit of Ihe present

inventioα However, such variations and modifications are all pertained to the scope of the present

inventioa

Industrial Applicability

As described above, according to the borehole drilling apparatus of the present invention, it is

possible to carry out high load and high speed drilling work because the extending wings advance and

retract in an in-line manner, and in particular, the sludge is not accumulated at the position where the

extending wings advance and retract

Also, it is possible to significantly reduce a working period required to finish Hie drilling of the borehole, considering that the conventional drilling apparatus has ftequently stop operation and has

been susceptible to disorder due to accumulation of the sludge.

In particular, when the sludge is accumulated between the extending wings to thereby block

smooth returning of fee extending wings, the whole drilling apparatus cannot be retracted from the borehole and it should be discarded, therefore, according to the present invention, it is possible to expect

a reduction of the costs caused by the lost of the equipments.

Claims

18What Is Claimed Is:

1. A borehole drilling apparatus with in-line extending wings, comprising a guide device,

wings for extending aboiehole, andapilotbit,

wherein the guide device is configured to be a cylindrical structure through which an air hole is

passed along a center axis thereof, and includes an upper shaft portion, a piston portion and a lower

shaft portion, wherein the piston portion is formed on the outer circumferential surface thereof with a

plurality of sludge discharging grooves; and the lower shaft portion is formed at the lower surface

thereof with spiral projections, 1he spiral projections each having a curved surface whose radius

increases ftom the center, and formed at a side thereof with a retaining protrusion and pin engaging

means; wherein the extending wing is wholly configured to be a rectangular structure, and is formed at

a side thereof with a guide groove for engaging slidably with the curved surface of the spiral projection

below tiie guide device; and wherein the pilot bit is configured to have a concave structure in which the lower shaft portion

of the guide device and the extending wings are received, the pilot bit being formed at a side thereof

with an advancing and retracting window for the extending wing, formed at the inner circumferential

surface thereof with a retaining step and pin engagement means for restricting the rotation of the guide

device by the retaining protrusion, formed at the lower surface thereof with an air hole, and formed at

the outer circumferential surface thereof with a plurality of sludge ά^harging grooves.

2. The drilling apparatus of claim 1, wherein the pin engagement means comprise pin

grooves, each of which is formed at positions corresponding to each oiher along the outer circumferential surface of the lower shaft portion in the guide device and the inner c^umferential

surface of the pilot bit, and a ring-type pin consisting of a plurality of arc-shaped pins inserted into the

pin grooves.

3. The drilling apparatus of claim 1, wherein the pin engagement means comprise insertion holes formed obliquely at side of the pilot bit, pin retaining grooves formed at the inner circumferential

surface of the pilot bit, insertion holes formed at the upper end of the lower shaft portion in the guide device to extend from Hie insertion holes of the pilot bit, pin receiving grooves formed at Hie inside of the insertion holes to correspond to the pin retaining grooves, securing pins engaged with the pin receiving grooves of the guide device and the pin retaining grooves of Hie pilot bit, and pin support rods inserted into the insertion holes.

4. The drilling apparatus of claim 1, wherein the extending wings installed are two or three in number.

5. A driving method of a borehole drilling apparatus comprising a guide device, wings for extending a borehole and a pilot bit, the driving method comprises the steps of: suppressing the rotation of the pilot bit by the frictional force produced when the extending wings rotate and descend integrally with the guide device in a state where Ihe extending wings are received in the pilot bit, and then a bottom surface of Hie pilot bit begins to strike a botom surface of the

borehole; spreading the extending wings outwardly from a wing advancing and retracting window

formed at a side of the pilot bit by the movement of the spiral projections formed at a lower surface of

the guide device along guide grooves formed at a side of the extending wings in Hie direction increasing radii of the spiral projections by the rotation force of Hie guide device, when the guide device continues

to rotate in a state where the rotation of the pilot bit is suppressed;

drilling the borehole with the integral rotation of the guide device, the extending wings and the

pilot bit, after the stop of the spread of the extending wings when an retaining protrusion formed on the

outer citcuraferenceofthe guide device is caught by aretaining step formed atthe intra

surface of the pilot bit;

suppressing the rotation of the extending wings by the fictional force produced when upper

surfaces of the extending wings comes into contact with a shoe of the casing to fit into the borehole,

after the guide device rotates reversely and ascends at the state of spread of the extending wings;

returning the extending wings into the wing advancing arκl extracting window of the pilot bit

by the movement of the spiral projections of the guide device along the guide grooves of the extending

wings in the direction decreasing radii of the spiral projections by the rotation force of the guide device,

when the guide device continues to rotate reversely in a state where the rotation of the extending wings

are suppressed; and retracting the guide device, the extending wings and the pilot bit from the casing while

integrally rotating them after the stopping of the return of the extending wings, when the retaining

protrusion formed on the outer circumference of tfie guide device contacts with the retaining step

formed at the inner circumferential surface of the pilot bit