Drilling device

Abstract

A drilling device for a down-the-hole drilling apparatus. The drilling device includes in a guide, a drilling member and a flushing mechanism configured to flush drilling waste. The drilling mechanism includes first and second drilling bit arrangements that are movable with respect to the drilling device and that are arranged to be expanded to drill a hole having a greater cross-sectional surface area than an end of the casing and arranged to be reduced to a size smaller than the end of the casing. Bit pieces of the second drill bit arrangement expand and reduce the second drill bit arrangement. The bit pieces expand the second drill bit arrangement by moving in a radial direction outwards in slide grooves, by rotating the guide in a drilling direction, and move in the radial direction inwards in the slide grooves, by rotating the guide in an opposite direction.

Claims

1. A drilling device that is meant to be used in a down-the-hole drilling apparatus for drilling a hole by using the drilling device and a casing part and a hammering device when needed, the drilling device comprising: in a drilling head thereof a guide, a drilling member, and a flushing arrangement configured to flush drilling waste being generated, wherein the drilling member comprises a first drill bit assembly and a second drill bit assembly, whereby the drill bit assemblies comprise drilling organs, wherein the second drill bit assembly is arranged to be expanded for drilling a greater hole than a free cross-sectional surface area of an end of the casing part and to be reduced to a smaller size than the free cross-sectional surface area of the end of the casing part in order to make possible removal of the drilling device from a hole that has been drilled and for leaving the casing part in the drilled hole by removing the drilling device through the casing part, whereby the second drill bit assembly comprises at least two bit pieces that are movable in a radial direction on a drilling surface of the drilling member, and the drilling organs are arranged in the bit pieces of the second drill bit assembly when viewed in a longitudinal direction of the drilling device on a front surface thereof, wherein the bit pieces of the second drill bit assembly are arranged, for expanding/reducing of the second drill bit assembly utilizing the guide, movable in slide grooves that pass in the radial direction on the drilling surface of the drilling member for expanding the second drill bit assembly by moving the bit pieces of the second drill bit assembly in the radial direction outwards in the slide grooves, by rotating the guide in a first direction in a drilling direction, and for reducing the second drill bit assembly by moving the bit pieces of the second drill bit assembly in the radial direction inwards in the slide grooves, by rotating the guide in a second direction opposite the first direction, wherein the slide grooves of the bit pieces of the second drill bit assembly are arranged either in an auxiliary frame, wherein the first drill bit assembly is arranged in an immovable manner relative to the guide, or in an intermediate frame, wherein the first drill bit assembly is in connection therewith, the frame being coupled with the guide rotatively in a restricted manner in a crosswise plane.

2. The drilling device according to claim 1, wherein the drilling organs of the first drill bit assembly are arranged in a built-in manner in the guide, and are arranged at an outer end of the guide operating as the drilling surface.

3. The drilling device according to claim 1, wherein the auxiliary frame is rotates via a pin/guide groove arrangement.

4. The drilling device according to claim 1, further comprising: a movement mechanism of the bit pieces of the second drill bit assembly, moving in the radial direction in a crosswise plane to the longitudinal direction of the drilling device, is arranged depending on the rotation direction of the guide to push the guide in the longitudinal direction out from the casing part or to pull the same inside the casing part, whereby the movements of the bit pieces of the second drill assembly in the radial direction are arranged by influence of a guide surface arrangement, being in connection with the bit pieces of the second drill assembly and both the casing part and an end of the guide.

5. The drilling device according to claim 1, wherein movement of the guide in the longitudinal direction, while being rotated in an opposite direction with respect to the drilling rotation direction, is arranged by a thread coupling carried out by a pin/guide groove arrangement between the guide and the auxiliary frame.

6. The drilling device according to claim 1, wherein the intermediate frame rotates via a pin/guide groove arrangement.

7. The drilling device according to claim 6, wherein the bit pieces of the second drill bit assembly that are movable in the crosswise plane, being perpendicular to the longitudinal direction of the drilling device, are coupled with slide grooves in the intermediate frame that comprises the drilling organs of the first drill bit assembly.

8. The drilling device according to claim 6, the movement of the drill bits of the second drill bit assembly in the radial direction are arranged by a movement mechanism between the guide and the bit pieces.

9. The drilling device according to claim 8, wherein the movement mechanism is arranged by a mutual pin/glide groove arrangement between an end surface of the guide and back surfaces of the bit pieces.

10. The drilling device according to claim 1, wherein the drilling organs comprise an integrated drilling part, separate drilling pieces, or bits.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Advantageous embodiments of the drilling device according to the invention have been presented herein.

(2) In the following description the invention is being described in detail with reference to the appended drawings, in which

(3) in FIGS. 1a and 1b is shown an advantageous drilling device according to the invention in its drilling position as a longitudinal cross section and as an end view,

(4) in FIGS. 2a and 2b is shown as perspective views an auxiliary frame and a drill bit of a drilling device according to FIGS. 1a, 1b,

(5) in FIGS. 3a and 3b is shown an advantageous alternative implementation of the drilling device according to the invention in its drilling position as a longitudinal cross section and as an end view,

(6) in FIGS. 4a and 4h is shown as perspective views an intermediate frame as seen from opposite directions belonging to a drilling device as shown in FIGS. 3a and 3b, and

(7) in FIGS. 5a and 5b are shown as advantageous embodiments perspective views of an end surface of the guide and a drill bit belonging to the drilling device according to FIGS. 3a and 3b.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(8) The invention relates to a drilling device that is meant to be used in a down-the-hole drilling apparatus for drilling a hole by using the drilling device 1 and a casing part 2 as well as a hammering device when needed. The drilling device 1 comprises in the drilling head I thereof a guide 4, drilling means 5 as well as advantageously flushing means for flushing of drilling waste being generated. The drilling means 5 comprise a first drill bit arrangement 5a and a second drill bit arrangement 5b that is movable with respect to the above, whereby the drill bit arrangements are provided with drilling organs 10, such as an integrated drilling part, separate drilling pieces, bits or the like. The second drill bit arrangement is arranged on the one hand to be expanded for drilling a greater t hole than a free cross-sectional surface area of an end I of the casing part 2 and on the other hand to be reduced to a smaller size than the free cross-sectional surface area of the end I of the casing part in order to make possible removal of the drilling device from a hole that has been drilled and for leaving the casing part 2 in the drilled hole by removing the drilling device 1 through the casing part 2 from above. The second drill bit arrangement 5b is arranged by two or more bit pieces that are movable in radial direction r on a drilling surface P of the drilling means, and in which the drilling organs 10; 10 are arranged when viewed in a longitudinal direction s of the drilling device on the front surface thereof.

(9) The bit pieces 5b1, being advantageously essentially elongated that is essentially longer than the width of the slide grooves U and belonging to the second drill bit arrangement 5b, are arranged, for expanding/reducing of the second drill bit arrangement 5b by means of the guide 4, movable in slide grooves U that pass wide open in the radial direction r on the drilling surface P of the drilling means 5 for expanding the second drill bit arrangement 5b by moving its bit pieces 5b1 in the radial direction r outwards in the slide grooves U, by rotating the guide 4 in one direction w in a drilling direction, and for reducing the second drill bit arrangement 5b by moving its bit pieces 5b1 in the radial direction inwards in the slide grooves U, by rotating the guide 4 in an opposite direction.

(10) As an advantageous embodiment of the drilling device according to the invention particularly with reference to FIGS. 1a, 1b, the first drill bit arrangement 5a is arranged in an immovable manner in connection with the guide 4, whereby as a furthermore advantageous embodiment, the drilling organs 10 of the first drill bit arrangement 5a, being arranged in a built-in manner in the guide 4, are arranged at an outer end of the guide 4 operating as the drilling surface P1.

(11) As a furthermore advantageous embodiment of this drilling device, the slide grooves U of the bit pieces 5b1 of the second drill bit arrangement 5b are arranged in an auxiliary frame R1 according to FIG. 2a, which is coupled with the guide 4 on the principle that manifests itself in FIG. 1a to rotate in a restricted manner in a crosswise plane x, such as by a pin/guide groove arrangement T1/01 or a like.

(12) Furthermore as an advantageous embodiment of the drilling device according to FIGS. 1a, 1b, a movement mechanism of the bit pieces 5b1 of the second drill bit arrangement, moving in the radial direction r in a crosswise plane x that is essentially perpendicular to the longitudinal direction s of the drilling device, is arranged depending on the rotation direction of the guide 4 to push the guide in the longitudinal direction s out from the casing part 2 or to pull the same inside the casing part 2, whereby the movements of the bit pieces in the radial direction r are arranged by influence of a guide surface arrangement y, being in connection with the bit pieces and both the casing part 2 and an end of the guide 4.

(13) The guide surface arrangement y mentioned above comprises for example in the embodiment according to FIG. 1a an edge gasket at the outer edge of the guide 4 as well as e.g. according to FIG. 2b inclined guide surfaces at the opposite ends of the bit pieces 5b1, which glide against an internal guide surface of the casing shoe 8 existing at the end of the casing part 2, when the guide 4 moves in the longitudinal direction s inside the casing part 2 as explained in the following.

(14) The embodiment according to FIGS. 1a, 1b is carried out furthermore advantageously in a way that the bits 10 at the end of the guide 4 are positioned in the longitudinal direction s to some extent deeper than the bits 10 of the second drill bit arrangement 5b, which has been found in practice to operate more profitably in drilling in some occasions than by placing the bits in totally the same plane. According to FIGS. 1a and 2b, the bits 10 at opposite ends of the bit pieces 5b1 are placed advantageously on inclined surfaces and so that the bits at the reaming end of the bit pieces are arranged to ream the drill being drilled according to FIG. 1 with an adequate clearance t with respect to the outer diameter of the casing shoe 8 at the end of the casing part 2.

(15) As a furthermore advantageous embodiment of the drilling device according to the invention, movement z of the guide 4 in the longitudinal direction s while the same is being rotated in an opposite direction with respect to the drilling rotation direction w, is arranged by a thread coupling carried out by a pin/guide groove arrangement T1/01 or a like between the guide 4 and the auxiliary frame R1, in which case the auxiliary frame has one or more thread grooves and the guide 4 has respectively one or more draw pins. The thread coupling in question, which is carried out advantageously by using draw pins to be installed in holes H in the auxiliary frame R1 after installation of the guide 4 and the auxiliary frame R1 on top of each other, works in practice in a drilling situation also as a power transmission arrangement transmitting the guide's 4 rotational motion to the auxiliary frame R1.

(16) As an alternative embodiment with respect to the one explained above with reference to the advantageous embodiment shown particularly in FIGS. 3a, 3b, the first drill bit arrangement 5a is arranged in an intermediate frame R2, which is coupled with the guide 4 to be movable with a restricted rotational movement in a crosswise plane x, such as by a pin/guide groove arrangement T2/02 or a like that manifests itself in FIGS. 3a and 4b. The above manifests itself in FIG. 4b, in which the intermediate frame R2 is shown from behind, according to which in the hole H in the intermediate frame R2 is fitted a pin T2 that moves in an elongated guide groove 02 in the guide 4.

(17) In this embodiment, the bit pieces 5b1 of the second drill bit arrangement that are movable in the crosswise plane x, as shown in FIG. 3b that is essentially perpendicular to the longitudinal direction s of the drilling device, are further advantageously coupled with slide grooves U, such as so called dovetail or T-grooves, in the intermediate frame R2 that comprises the drilling organs 10 of the first drill bit arrangement 5a, which grooves hold the bit pieces also axially s (which principle applies naturally also to the bit pieces of the embodiment according to FIGS. 1a, 1b).

(18) As a further advantageous embodiment of the drilling device according to FIGS. 3a, 3b, the movement of the drill bits 5b; 5b1 of the second drill bit arrangement in the radial direction r are arranged by a movement mechanism between the guide 4 and the bit pieces 5b1.

(19) The movement mechanism in question is arranged by a mutual pin/glide groove arrangement T3/03 between an end surface 4a of the guide 4 and back surfaces of the bit pieces 5b1 or in a corresponding manner, wherein with reference particularly to FIGS. 5a and 5b, the movement mechanism has been carried out in this case by guide grooves 03 at the end surface of the guide 4, which depending on the rotating direction of the guide 4 transmit the bit pieces' 5b1 movement in radial direction in the slide grooves U in co-operation with pins T3 in the bit pieces. On the end surface 4a of the guide there has also been arranged flow ways 6 for leading of the flushing medium, being brought centrically, to the drilling device's drilling surface P in radial direction, on the outer surface of the guide guided by the end surfaces of the bit pieces and through the slide grooves U in the intermediate frame R2.

(20) It is clear that the invention is not limited to those embodiments, being presented or described above, but instead it can be modified significantly within the basic idea. It is thus possible e.g. to use on the drilling surfaces of the drilling device more frame parts than shown in the drawings or to exploit the embodiments shown in FIGS. 1a, 1b and 3a, 3b in a mixed manner one way or another e.g. by using wider or narrower bit pieces. Correspondingly in connection with the end of the casing part there is not necessarily a need to use a separate casing shoe, but instead the corresponding arrangements can be formed e.g. with arrangements fixed on the outer and/or internal surfaces of the end of the casing part. By arranging the flushing flows according to the principles shown in the drawings an efficient flow of the flushing medium into the spaces that will be left open between the drilling parts has been tried to achieve, so that material may not get collected therein. This influence may be made more efficient by using a more abundant flushing flow channel system than presented above or by carrying out the flushing flow channel system to operate by so called reverse flow. In the drilling device according to the invention it is possible to exploit parts manufactured by utilizing most heterogeneous manufacturing techniques by using customary used materials.