DRILLING TOOL AND METHOD FOR CREATING A BORE IN THE GROUND

Abstract

The invention relates to a drilling tool for creating a bore in the ground, having a tubular drill shank, at least one removal device which is configured to remove ground material, a supply device for supplying a fluid through the drill shank through at least one outlet opening for the fluid into the bore and at least one mixing element which extends radially to the drill shank, is arranged on the drill shank above the removal device and is configured to mix ground material with the fluid. According to the invention, it is provided that at least one first outlet opening is arranged in the region of the removal device and at least one second outlet opening is arranged at an axial distance from the at least one first outlet opening and at least one actuating device is provided on the supply device, by means of which the at least one first outlet opening and/or the at least one second outlet opening can be blocked, wherein fluid can optionally be introduced into the bore via the at least one first outlet opening and/or the at least one second outlet opening.

Claims

1.-14. (canceled)

15. A drilling tool for creating a bore in the ground, comprising a tubular drill shank, at least one removal device, which is configured to remove soil material, a supply device for supplying a fluid through the drill shank through at least one outlet opening for the fluid into the bore, and at least one mixing element extending radially to the drill shank, which is arranged on the drill shank at an axial distance from the removal device and is configured for mixing soil material with the fluid, wherein at least one first outlet opening is arranged along the drill shank in the region of the removal device and at least one second outlet opening is arranged along the drill shank at an axial distance from the at least one first outlet opening, wherein at least one actuating device is provided on the supply device, by means of which the at least one first outlet opening and/or the at least one second outlet opening can be blocked, wherein fluid can optionally be introduced into the bore via the at least one first outlet opening and/or the at least one second outlet opening and the at least one first outlet opening and the at least one second outlet opening can alternately be blocked by the at least one actuating device, wherein fluid can be introduced into the bore via the at least one first outlet opening and/or the at least one second outlet opening, while the at least one second outlet opening or rather the at least one first outlet opening is blocked.

16. The drilling tool according to claim 15, wherein at least one first removal device is arranged at a lower end portion of the drill shank and at least one second removal device is arranged axially above the first removal device.

17. The drilling tool according to claim 16, wherein the at least one mixing element is arranged between the first removal device and the second removal device.

18. The drilling tool according to claim 15, wherein the removal device has at least one support bar extending radially to the drill shank, on which removal elements for removing soil material are arranged, and a first conduit channel is formed on or in the support bar, along which further outlet openings are provided.

19. The drilling tool according to claim 15, wherein the mixing element has a support arm and a second conduit channel is formed on or in the support arm, along which further outlet openings are provided.

20. The drilling tool according to claim 15, wherein at least one outlet opening is arranged directly on the drill shank.

21. The drilling tool according to claim 15, wherein the actuating device comprises at least one movable actuating element which can be adjusted between a closed setting and an open setting.

22. The drilling tool according to claim 21, wherein an actuating element is assigned to each conduit channel.

23. The drilling tool according to claim 15, wherein the actuating device can be operated by changing the rotation of the drill shank.

24. The drilling tool according to claim 21, wherein the at least one actuating element is mechanically adjustable by means of a link adjusting mechanism.

25. A method for creating a bore in the ground, wherein a drilling tool according to claim 15 is used and a fluid is optionally introduced into the bore via at least one first outlet opening and/or at least one second outlet opening.

26. The method according to claim 25, wherein during sinking-by-drilling the fluid is introduced via the at least one first outlet opening, which is arranged in a lower end portion of the drill shank, and the fluid is introduced into the bore via the at least one second outlet opening above the first outlet opening, wherein the drilling tool is rotated.

27. The method according to claim 25, wherein a curable suspension is introduced as a fluid, wherein a foundation element is produced in the bore in the ground.

Description

[0026] The invention is explained further below with reference to a preferred exemplary embodiment. The drawings show in:

[0027] FIG. 1 a side view of a drilling tool according to the invention;

[0028] FIG. 2 a view of the drilling tool in FIG. 1 from below;

[0029] FIG. 3 a cross-sectional view of the drilling tool according to FIGS. 1 and 2; and

[0030] FIG. 4 an enlarged detailed view corresponding to the marked detail in FIG. 3 of the actuating device of a drilling tool according to the invention.

[0031] A drilling tool 10 according to the invention is explained in conjunction with FIGS. 1 to 4. The drilling tool 10 comprises a tubular drill shank 12 with an inner cavity 14. A central pilot tip 20 and a downwardly directed first removal device 21 are arranged on an underside of the drill shank 12. The first removal device 21 has a short drill helix 18 with two passage openings 19. Tooth-like removal elements 26 for removing soil material are arranged along two first support bars 24 extending in a radial direction in a manner known per se. The first support bars 24 are designed hollow and form a first conduit 32, which extends in a radial direction. The first conduit 32 is connected to a central supply device 30 with a central conduit 31 in the hollow drill shank 12 for supplying a liquid or suspension. The liquid or suspension can flow out along the first support bars 24 via first outlet openings 35.

[0032] A plug-like drill pipe connection 16 is arranged at an upper end of the drill shank 12, in order to connect the drilling tool 10 to a hollow drill pipe, not shown, which is rotatably mounted and driven in a manner known per se on a preferably mobile drilling rig. Liquid or suspension can be fed from the drilling rig via the drill pipe to the supply device 30 in the drilling tool 10.

[0033] Directly below the drill pipe connection 16 is arranged an upward-directed second removal device 22 with tooth-like removal elements 26. In contrast to the removal elements 26 of the first removal device 21, the removal elements 26 of the second removal device 22 are directed upwards, in order to crush soil material that maybe have fallen in during rotatingly withdrawing of the drilling tool 10 from a created borehole and to ensure a reliable withdrawing of the drilling tool out of a bore in the ground.

[0034] The second removal device 22 can also have two opposing and radially directed second support bars 25, which are designed hollow in order to form a second conduit channel 33. The second conduit channels 33 open out into the central conduit 31 of the supply device 30, as clearly illustrated in FIG. 4.

[0035] Between the first removal device 21 and the second removal device 22, axially and/or radially offset mixing elements 40 with radially directed support arms 42 are formed on the drill shank 12, on which mixing blades 44 can be arranged.

[0036] Below the second removal device 22, an actuating device 50 with a bolt- or plate-shaped actuating element 52 is formed on the drill shank 12, by means of which the center line 31 of the supply device 30 between the first removal device 21 and the second removal device 22 can be shut-off or opened. In FIGS. 3 and 4, the actuating element 52 is shown in the closed or blocked position. One end of the actuating element 52 projects out of the drill shank 12, wherein a radially upwardly directed cam bolt 56 is provided at the outwardly projecting end to form a link adjusting mechanism 54.

[0037] The cam bolt 56 engages in a guide groove 59 in an arcuate link rail 58, which is arranged on the outside of the drill shank 12. The guide groove 59 runs in the circumferential direction and is approximately semicircular in shape, but with a varying distance from the drilling axis. This forms the link adjusting mechanism 54, wherein a relative rotation between the link rail 58 with the guide groove 59 and the cam bolt 56 changes the radial position of the latter relative to the drilling axis. The connection between the cam bolt 56 and the actuating element 52 allows the latter to be adjusted between a closed position and an open position by relative rotation.

[0038] To effect a relative rotation, the arcuate link rail 58 can be attached to a bearing sleeve 60, which is rotatably mounted on the outside of the drill shank 12. The upper second removal device 22 can also be arranged on the bearing sleeve 60. When the direction of rotation of the drilling tool 10 is changed, a relative rotation can thus be effected between the drill shank 12 and the bearing sleeve 60 with the link rail 58 and, if applicable, the second removal device 22 attached thereto. Thus, the actuating device 50 can be actuated by changing the direction of rotation of the drilling tool 10.

[0039] According to a method according to the invention, the actuating element 52 can thus be brought into its open position when creating and deepening a bore with the drilling tool 10, so that in this position drilling fluid or drilling suspension can be guided to the lower first outlet openings 35 during sinking-by-drilling and can be introduced directly into the bore at the first removal device 21.

[0040] If, on the other hand, the drilling tool 10 is retracted again from the bore with the direction of rotation reversed, the link adjusting mechanism 54 causes the actuating element 52 to be adjusted into a closed or locked position, so that liquid or suspension then fed is introduced into the bore exclusively via the above-located second outlet openings 36 on the second removal device 22.

[0041] The introduction at the upper end of the drilling tool 10 ensures that the rotating drilling tool 10 still admixes the newly introduced fluid sufficiently intensively with the existing suspension in the bore during retraction.