Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
DRILLING DEVICE FOR EARTH DRILLING
Document Type and Number:
WIPO Patent Application WO/2011/144807
Kind Code:
A1
Abstract:
This invention relates to a drilling device for earth drilling, which comprises a casing part (2) to be placed in a hole to be drilled and a drilling unit (3) in connection with the above during a drilling situation, whereby at a drilling head of the drilling unit there are a drill bit (4) that is to be left after the drilling of the hole at the end of the casing part on the bottom of the hole and a flushing flow arrangement (6) at least for leading of a flushing medium for drilling onto the drill bit's drilling surface (4p), in order to carry out drilling by using the drill bit with a rotational motion (w4), a feeding motion (z4) and/or a hammering motion (t4) and, when the drilling depth increases, by coupling with the drill bit or a hammering device coupled therewith and thereafter with each other successive drill rods in a longitudinal direction (s). In the longitudinal direction (s) behind the drill bit (4) is arranged a separate closing assembly (x) in order to prevent contrary flow through the flushing flow arrangement (6) particularly, when the drilling is interrupted, such as when a drill rod is added or in a corresponding situation, by closing a flow arrangement that connects the flushing flow arrangement (6) with the drill bit's drilling surface (4p).

Inventors:
AHONEN, Jukka (Riihipellonkatu 4 C 21, Tampere, FI-33530, FI)
Application Number:
FI2011/050438
Publication Date:
November 24, 2011
Filing Date:
May 12, 2011
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
OY ATLAS COPCO ROTEX AB (Pihtisulunkatu 1 A, Tampere, FI-33330, FI)
AHONEN, Jukka (Riihipellonkatu 4 C 21, Tampere, FI-33530, FI)
International Classes:
E21B21/10
Attorney, Agent or Firm:
KANGASMÄKI, Reijo (Patenttikonsultointi Kangasmäki Oy, PL 25, Tampere, FI-33401, FI)
Download PDF:
Claims:
Claims :

1. Drilling device for earth drilling comprising a casing part (2) to be placed in a hole to be drilled and a drilling unit (3) in connection with the above during a drilling situation, whereby at a drilling head of the drilling unit there are a drill bit (4) that is to be left after the drilling of the hole at the end of the casing part (2) on the bottom of the hole and a flushing flow arrangement (6) at least for leading of a flushing medium for drilling onto the drill bit's drilling surface (4p) , in order to carry out drilling by using the drill bit (4) with a rotational motion (w4) taking place continuously in a same direction, a feeding motion (z4) and/or a hammering motion (t4) and, when the drilling depth increases, by coupling with the drill bit (4) or a hammering device coupled therewith and thereafter with each other successive drill rods in a longitudinal direction (s) , and whereby in the longitudinal direction (s) behind the drill bit (4) is arranged a separate closing assembly (x) in order to prevent contrary flow through the flushing flow arrangement (6) particularly, when the drilling is interrupted, such as when a drill rod is added or in a corresponding situation, by closing a flow arrangement that connects the flushing flow arrangement (6) with the drill bit's drilling surface (4p), characterized in that, the closing assembly (x) comprises a locking means (xl) in order to switch on the closing action by rotating the drill bit (4) in an opposite direction with respect to its rotational motion (w4) during drilling in order to move the locking means (xl) from a flushing position (I) into a closing position (II) that closes the flow arrangement in the drill bit (4) .

2. Drilling device according to claim 1, characterized in that, the closing assembly (x) comprises a guide (x2) to be coupled removably in connection with the drill bit (4) .

3. Drilling device according to claim 2, characterized in that, the guide (x2) comprises a coupling means (x3) functioning in co-operation with counterpart means (V) in the drill bit (4) in order to couple the guide with the drill bit (4) in a lockable and releasable manner in the longitudinal direction (s) .

4. Drilling device according any of the preceding claims 1-3, characterized in that the locking means (xl) comprises a locking ring that is coupled rotatively (r) on a stem (4a) of the drill bit (4) .

5. Drilling device according to claim 4, characterized in that, the locking ring (xl) and the drill bit (4) have a mutual movement restriction arrangement (x4) for placement of the locking ring into the flushing position (I) and the closing position (II) .

6. Drilling device according to any of the preceding claims 1-5, characterized in that, the drill bit's drilling surface (4p) is provided with both input and output flow ways for the flushing flow arrangement (6; 6a, 6b), which ways are both arranged to be closed simultaneously by the closing assembly (x) . 7. Drilling device according to any of the preceding claims 3-5, characterized in that, the coupling means (x3) and the counterpart means (V) are arranged by a longitudinal (s) groove (x3u) at an end of the guide (x2), whereby at an end of the groove there is an extended cavity (x3o) for a locking projection (Vo) on the stem (4; 4a) of the drill bit.

8. Drilling device according to any of the preceding claims 1-7, characterized in that, the casing part (2) is arranged to be drawn into the hole by transmission of the drilling unit (3) .

9. Drilling device according to claim 8, characterized in that, a shoulder arrangement (2a) is arranged at the end of the casing part (2) in order to pull the same into the hole by transmission of a pulling counterpart surface (x2a) in the guide (x2) .

Description:
Drilling device for earth drilling

The invention relates to a drilling device for earth drilling, which comprises a casing part to be placed in a hole to be drilled and a drilling unit in connection with the above during a drilling situation, whereby at a drilling head of the drilling unit there are a drill bit that is to be left after the drilling of the hole at the end of the casing part on the bottom of the hole and a flushing flow arrangement at least for leading of a flushing medium for drilling onto the drill bit's drilling surface, in order to carry out drilling by using the drill bit with a rotational motion, a feeding motion and/or a hammering motion and, when the drilling depth increases, by coupling with the drill bit or a hammering device coupled therewith and thereafter with each other successive drill rods in a longitudinal direction.

E.g. in patent No. US 6,182,776 is described a system and assembly suitable for a drilling purpose described above. The drilling assembly comprises a drilling device, which has a casing part, inside which is a drilling unit that in it's drilling head has a drill bit for drilling a hole, a flushing flow arrangement for leading out drilling waste by the effect of a flushing medium at least in a partly uprising manner along the inner side of the drilling device and a pressure medium operated hammering device for transmitting the hammering motion to the drill bit. In this solution the casing part is arranged to be pulled into the drilling hole by the drilling unit. The drilling equipment also comprises a water-driven hammering device. When building structures, especially in a soil with a high water pressure, there is often a need for injecting of the soil, which is done e.g. with upward drilling from inside of a tunnel. When drilling, the casing part is left in the hole that is drilled to lead the injecting mass to the ground in order to firm the soil. At present, however, this type of drilling includes significant safety risks. One major problem is that the drill bit's flushing grooves are left open e.g. when the drill rods are changed thus allowing water from the soil to flow through the drilled hole. In that case, depending on the amount of the water leakage, it may cause a safety risk to the drilling staff.

The purpose of the drilling device according to the present invention is to provide a conclusive improvement to the above problem and thereby substantially to raise the present level of technique in the field. To fulfil this purpose, the drilling device according to the invention is characterized in that, in the longitudinal direction behind the drill bit is arranged a separate closing assembly in order to prevent contrary flow through the flushing flow arrangement particular- ly, when the drilling is interrupted, such as when a drill rod is added or in a corresponding situation, by closing a flow arrangement that connects the flushing flow arrangement with the drill bit's drilling surface. The most important advantages of the drilling device according to the invention are its simple and steady usage, which allows significant improvement in the safety of the drilling situations, especially when drilling soil with high water pressure. The drilling device according to the invention includes a closing assembly that is arranged to work advantageously e.g. by a locking ring that can be used to switch on a closing action simply by e.g. rotating the drill bit in an opposite direction with respect to its rotational motion. As an further advantageous embodiment the closing assembly comprises a guide to be coupled removably in connection with the drill bit, which in co-operation with the drill bit and the locking means coupled with it allow the closing action in the drill bit and also a fast and effective coupling of the drill bit/hammering device and the drill rods.

Other advantageous embodiments of the invention are described in the dependent claims.

In the following description the invention is demonstrated in detail concurrently referring to the appended drawings, in which in figure 1

is shown a perspective view of an assembly of one advantageous drilling device according to the invention, in figure 2

is shown the assembly according to figure 1 in an longitudinal section view when the closing assembly of the drilling device is in a flushing position, in figure 3

is shown the assembly according to figure 2 when the closing means is in a closing position, in figure 4

is shown a longitudinal section view of one alternative embodiment of the drilling device according to the invention when the closing assembly is in a flushing position, in figure 5

is shown the embodiment according to figure 4 when the closing assembly is in a closing position, in figures 6 and 6b

is shown the drilling surface of the embodiment according to figure 1 as a rear view, the closing assembly being in a flushing position and in a closing position.

The invention relates to a drilling device for earth drilling, comprising a casing part 2 to be placed in a hole to be drilled and a drilling unit 3 in connection with the above during a drilling situation, whereby at a drilling head of the drilling unit there are a drill bit 4 that is to be left after the drilling of the hole at the end of the casing part 2 on the bottom of the hole and a flushing flow arrangement 6 at least for leading of a flushing medium for drilling onto the drill bit's drilling surface 4p, in order to carry out drilling by using the drill bit 4 with a rotational motion w4, a feeding motion z4 and/or when needed with a hammering motion t4 and, when the drilling depth increases, by coupling with the drill bit 4 or a hammering device coupled therewith and thereafter with each other successive drill rods in a longitudinal direction s. In the longitudinal direction s behind the drill bit 4 is arranged a separate closing assembly x in order to prevent contrary flow through the flushing flow arrangement 6 particularly, when the drilling is interrupted, such as when a drill rod is added or in a corresponding situation, by closing a flow arrangement that connects the flushing flow arrangement 6 with the drill bit's drilling surface 4p.

As an advantageous embodiment of the drilling device according to the invention, the drilling takes place by continuously rotating the drill bit 4 in the same di- rection w4. Then, the closing assembly x further advantageously comprises a locking means xl in order to switch on the closing action by rotating the drill bit 4 in an opposite direction with respect to its rota- tional motion w4 during drilling in order to move the locking means xl from a flushing position I shown in figures 2, 4 and 6a into a closing position II shown in figures 3, 5 and 6b that closes the flow arrangement in the drill bit 4.

As a further advantageous embodiment of the drilling device according to the invention, referring especially to the advantageous composition shown in figure 1, the closing assembly x comprises a guide x2 to be coupled removably in connection with the drill bit 4, which as a further advantageous embodiment comprises coupling means x3 functioning in co-operation with counterpart means V in the drill bit 4 in order to couple the guide with the drill bit 4 in a lockable and releasable manner in the longitudinal direction s.

As an especially advantageous embodiment, especially according to figure 1, the locking means xl comprises a locking ring that is coupled rotatively r on a stem

4a of the drill bit 4. The locking ring xl and the drill bit 4 have a mutual movement restriction arrangement x4 for placement of the locking ring into the flushing position I and the closing position II. The movement restriction arrangement x4 is advantageously arranged with a projection on the front edge of the locking ring that rotates in a sliding groove on the back of the drill bit 4, whereby the rotation angle is restricted by its back edges.

In the advantageous embodiments shown especially in figures 1-3 and 6a, 6b, the drill bit's drilling surface 4b is provided with both input and output flow ways for the flushing flow arrangement 6; 6a, 6b, which ways are both arranged to be closed simultaneously by the closing assembly x, as shown in figure 2. As a further advantageous embodiment especially according to figure 1, the coupling means x3 and the counterpart means V are arranged by a longitudinal s groove x3u at an end of the guide x2, whereby at an end of the groove there is an extended cavity x3o for a locking projection Vo on the stem 4; 4a of the drill bit. When using the drilling device, the drill bit's locking projection Vo is locked in an axial direction x on the other side of the cavity x3o and accordingly locked on the opposite side of the cavity x3o in a similar manner when the drilling device rotates to the opposite direction activating the closing action II. When uncoupling the guide x2 and the drill rod arrangement attached to it, the drill rod arrangement and the drill bit 4 at the end of it and the possible hammering device are rotated in a way that the locking projection Vo reaches the groove x3u, which releases the drill rod arrangement and the guide for the pulling thereof out of the drilled hole.

As a further advantageous embodiment, especially according to figures 4 and 5, the casing part 2 is arranged to be drawn to the hole by transmission of the drilling unit 3, wherein a shoulder arrangement 2a is arranged at the end of the casing part 2 in order to pull the same into the hole by transmission of a pulling projection x2a in the guide x2.

It may still be possible that water is flown in the closing assembly's x closing actions II shown in figures 3 and 5 from between the casing part 2 and the drill unit's 3 neck. For this, as a further advantageous embodiment, an inset sv is arranged in the back edge of the locking ring xl against the end of the casing part 2, whereby the contact in question as shown with a dashed line in figure 4 is achieved either by pushing the casing part into the hole or by pulling y the drill bit 4 backwards. It is clear that the invention is not restricted to the embodiments described or explained above, but it may be adjusted to fit the drilling techniques used in a most suitable manner at any given time within the limits of the dependent claim. There are a number of variations of the drilling device according to the invention, because the drilling may be executed on the down the hole -principle for the part of both the hammering motion and the casing part or in other words the protecting tube, when the same is fed into the ground, with arrangements on the drill bit or by carrying out either one or both of these actions from the drill rods' feeding end. Furthermore, the closing assembly according to the invention may also be executed in other ways, such as to be used with a longitudinal motion, and/or by using e.g. a suitable rotative joint or a bayonet coupling between the guide, the locking means and the drill bit etc.