Rotary drilling tool and method for producing a bore

Abstract

The invention relates to a rotary drilling tool and to a method for producing a borehole in the ground, having a base body, a removal device which has at least one hammer unit which comprises a hammer element driven in axially reversing manner, and a discharge line for discharging removed ground material and drilling suspension. According to the invention it is provided that a pumping device is arranged on the base body along the discharge line, and that the pumping device is configured for pumping off the removed ground material with drilling suspension through the discharge line.

Claims

1. A rotary drilling tool for producing a bore in the ground, comprising: a base body; and a discharge line for discharging removed ground material and drilling suspension, wherein a pumping device is arranged on the base body along the discharge line, the pumping device being configured for pumping off the removed ground material with a drilling suspension through the discharge line, a removal device is arranged on an underside of the base body, the removal device comprising a plurality of hammer units which each comprise a hammer element driven in axially reversing manner, the hammer elements each comprise a vertically oriented piston which is in each case displaceably mounted in a cylinder housing of the hammer unit, multiple extraction openings, for extraction of the removed ground material, are arranged on an underside of the base body, and an energy supply line is provided such that the pumping device on the base body is supplied with electrical energy or hydraulic energy.

2. The rotary drilling tool according to claim 1, wherein the hammer units are operated with compressed air supplied via a supply line.

3. The rotary drilling tool according to claim 2, wherein an outlet opening for used compressed air is provided at a lower end region of the hammer units.

4. The rotary drilling tool according to claim 1, wherein the pumping device is arranged above the removal device in a housing.

5. The rotary drilling tool according to claim 4, wherein a connecting device for a drill string is arranged on an upper side of the housing.

6. The rotary drilling tool according to claim 1, wherein the pumping device is arranged on a central portion of the discharge line, and beneath the central portion, the discharge line divides into a plurality of discharge sub-lines.

7. The rotary drilling tool according to any claim 6, wherein each extraction opening is connected with a discharge sub-line, which leads to the central section with the pumping device.

8. The rotary drilling tool according to claim 1, wherein the rotary drilling tool is in the form of a full-face drilling tool.

9. The rotary drilling tool according to claim 1, wherein the rotary drilling tool is in the form of a core drilling tool.

10. A method for producing a bore in the ground by means of the rotary drilling tool according to claim 1, wherein ground material is removed by means of the removal device on the underside of the base body of the rotary drilling tool, the removed ground material and a drilling suspension are discharged by means of a discharge line, and the pumping device is arranged on the base body of the rotary drilling tool along the discharge line such that the removed ground material with the drilling suspension is pumped through the discharge line to the outside of a borehole.

11. The method according to claim 10, wherein at least one hammer unit is operated with compressed air which emerges at an underside of the base body.

12. The method according to claim 10, wherein the removed ground material and the drilling suspension are extracted via the plurality of extraction openings and a plurality of discharge sub-lines which open into a central portion on which the pumping device is arranged.

Description

(1) The invention will be described further hereinbelow with reference to preferred exemplary embodiments which are shown schematically in the drawings, in which:

(2) FIG. 1 is a perspective view of a first rotary drilling tool according to the invention;

(3) FIG. 2 is a perspective view of the rotary drilling tool of FIG. 1 without a housing;

(4) FIG. 3 is a sectional view of the rotary drilling tool of FIG. 1 in a longitudinal section;

(5) FIG. 4 is a perspective view of a second rotary drilling tool according to the invention;

(6) FIG. 5 is a perspective view of a rotary drilling tool of FIG. 4 without a housing;

(7) FIG. 6 is a sectional view of the rotary drilling tool of FIG. 4 in a longitudinal section;

(8) and

(9) FIG. 7 is a sectional view of the rotary drilling tool of FIG. 4 in a cross-section transversely to the longitudinal axis.

(10) A first rotary drilling tool 10 according to the invention is described hereinbelow in conjunction with FIGS. 1 to 3. The rotary drilling tool 10 is in the form of a core drilling tool with an annular arrangement of the removal device 20 around a central hollow core receptacle 16. In the exemplary embodiment shown, the removal device 20 has six hammer units 22 of identical construction having a circular disc-shaped hammer element 24. On the underside of the axially movable hammer elements 24 there are arranged removal elements (not shown in greater detail), which are preferably acute tapering cemented carbide elements. Between the individual hammer units 22 there are arranged extraction openings 38 for the extraction of the removed ground material with surrounding drilling suspension. The extraction openings 38 are angled in a direction of rotation in order to achieve a material uptake as good as possible.

(11) The rotary drilling tool 10 comprises a cylindrical housing 14, at the upper end of which there is mounted a connecting device 50 for a drill string. The connecting device 50 is preferably in the form of a so-called Kelly box for receiving a square end of a drill string.

(12) As is shown clearly in FIG. 2, the individual hammer units 22 have an elongate cylindrical cylinder housing 28 in which a piston 26 is displaceably mounted in reversing manner between a lower striking position and an upper pull-back position. The disc-shaped hammer element 24 is attached to a lower end of the piston 26, which is merely indicated in FIG. 3.

(13) The hammer units 22 are supplied with compressed air via a supply line 29. The supply line 29, which runs vertically upwards outside the borehole, opens at its lower end into a transverse line 27 which leads to the individual hammer units 22. The transverse line 27 is formed between two cover plates. At a lower end region of the hammer units 22, used compressed air can emerge at the underside of the base body 12 of the rotary drilling tool 10.

(14) Removed ground material and surrounding drilling suspension as well as emerging compressed air are discharged via the obliquely-directed extraction openings 38 via the individual discharge sub-lines 34. The discharge sub-lines 34 are thereby connected via transverse channels 35 to a central portion 32 of an upwardly guided discharge line 30. A pumping device 40 arranged centrally in the housing 14 is positioned on the central portion 32. The pumping device 40 is provided via an energy supply line 44 with driving energy, in particular electrical energy, from a carrier device outside the borehole. From the central portion 32, the ground material taken in is carried upwards by the pumping device 40 via the discharge line 30. The pumping device 40 is fixedly connected to the base body 12 of the rotary drilling tool 10 via a pump housing 42 and the central portion 32.

(15) FIGS. 4 to 7 show a second rotary drilling tool 10 according to the invention, which is in the form of a full-face drilling tool. The rotary drilling tool 10 has a cylindrical housing 14, at the lower end of which there is arranged a removal device 20 which extends substantially transversely over a circular disc-shaped base plate 18. The removal device 20 is formed of a plurality of hammer units 22 having circular disc-shaped hammer elements 24. Furthermore, two radially extending slot-like extraction openings 38 for the extraction of removed ground material and surrounding ground suspension are arranged on the base plate 18. As in the rotary drilling tool 10 described hereinbefore, a Kelly box is attached to the upper side of the housing 14 as a connecting device 50 for a drill string.

(16) Inside the cylindrical housing 14, which in this rotary drilling tool 10 constitutes a substantial portion of the base body 12, there are arranged the rod-shaped hammer units 22 with their respective cylinder housings 28. Inside the cylinder housings 28 there are mounted in axially reversing manner pistons 26 driven by compressed air for exerting a striking movement on the in-situ working area. Disc-shaped hammer elements 24 having removal elements (not shown) are attached to the lower ends of the pistons 26.

(17) Removed ground material is extracted via the two elongate extraction openings 38. In the present exemplary embodiment, the pumping device 40 has two separate pumps 41, each pump 41 being line-connected via its own discharge line 30 to a suction opening 38.

(18) For supplying compressed air to the hammer units 22 there is provided a supply line 29 which extends upwards and opens in its lower region into a central pipe portion 25, which is formed beneath the connecting device 50. Fed compressed air is guided further from the pipe portion 25 via a transverse line 27 formed in a cover plate 17 to the individual hammer units 22.

(19) In operation, the rotary drilling tool 10 is driven in rotation via a drill string (not shown), so that the removal device 20 with the hammer units 22 sweeps over the entire in-situ working area.