DE2924392A1 - DRILLING DEVICE FOR OVERLAY DRILLING - Google Patents

Description

VON KREISLER SCHÖNWALD EISHOLD IgJJJ ^ 39 2 FROM KREISLER KELLER SELTING WERNER

Applicant

PATENT LAWYERS

Ing.Günter Klemm Dr.-Ing. by Kreisler11973 Special company for

Bohrtechnik ^ S ^ SS

5961 Drolshagen / Wenkhausen Dr. J. F. Fues, Cologne

Dipl.-Chem. Alek von Kreisler, Cologne

,., .., " ,. "," Dipl.-Chem. Carola Keller, Cologne

Bruckner Grundbau GmbH _n . ,. _{n c} ... "..,

,,. "" Dipl.-Ing. G. belting, Cologne

Colliery Ernestine 2 9 Dr. H.-K. Werner, Cologne

4300 Essen 1

DEICHMANNHAUS AT THE MAIN RAILWAY STATION

D-5000 COLOGNE 1

June 15, 197 9 Sg / En

The invention relates to a drilling device for overlay drilling, with an inner pipe rod running in an outer pipe rod, at the end of which a drilling tool is attached striking downhole hammer is attached, and with a rotary drive rotating the inner pipe rod.

There are known drilling devices for superimposition drilling in which the inner pipe rod has a downhole hammer and is coupled to the outer pipe rod via an annular shoulder for impact transmission. Both tubes are from rotated a rotary drive. As a result of the vibration vibrations transmitted to the outer pipe rod, the outer pipe rod Vibrations exerted on the surrounding soil. These vibrations mainly affect rolling ground types Soil compaction, which in turn subsidence

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Telephone: (02211 13W41 TeW. 888230? Dopa d · Telegram: Dompatent Cologne

ORIGINALiNSPECTED

may result. It has been shown that as a result of overburden drilling, soil compaction can occur, which has an impact on the course of the groundwater and can change it. The changes in the soil can lead to settlement phenomena, e.g. on neighboring buildings and ground shifts.

In the case of overlay drilling, this drills on the inner pipe rod attached drilling tool a larger borehole, the width of which is sufficient to accommodate the outer pipe rod. In order to be able to generate the required large borehole diameter, it is known to use eccentric drill bits. These are drill bits that are eccentrically attached to one along the axis of the drill string extending shaft are attached. An eccentric drill bit can pass through the outer pipe string be pulled up, but is still capable of a borehole to drill the diameter of which is equal to or greater than that of the outer pipe rod. Such Drilling jigs can be provided with either an outside hammer or a downhole hammer. In any case are the inner pipe rod and the outer pipe rod over impact shoulders with which they butt against each other, coupled, so that the distribution of both rods takes place under impact. Here too, the ones mentioned above occur Changes in the soil structure.

Finally, it is known to use a full drilling tool for overlay drilling, which over the contour of the Outer pipe rod protrudes and is provided with a predetermined breaking element. Should the inner pipe rod be pulled up

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then it is released from the drilling tool, which tears off and remains in the borehole. While eccentric drilling tools generally have an imprecise directional guidance is not an exact directional guidance with solid drilling tools possible.

The object of the invention is to create a drilling device of the type mentioned at the outset which, in spite of its use a hammer drill affects the soil structure in the vicinity of the borehole as little as possible in order to avoid the damage mentioned to avoid and to achieve directional drilling.

To solve this problem it is provided according to the invention that an independent second rotating the outer pipe linkage Rotary drive is provided and the outer pipe rod is suddenly decoupled from the inner pipe rod that both Rotary drives are mounted on a powered feed device and that the drilling tool is one in the borehole is detachable lost drilling tool.

The feed device effects the axial feed of the outer pipe rod. Here the outer pipe rod pushed into the enlarged borehole previously made by the drilling tool. The pushing in of the outer tube rod takes place without impact, so that no vibrations are transmitted to the ground. The outer pipe linkage, that is rotated separately, can thus be advanced in the rotating state while the drilling tool drills and hits at the same time. The outer pipe rod, on which no blows are exerted, serves at the same time as noise insulation for acoustic insulation of the interior

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pipe rod, so that the drilling device as a whole also developed a lower noise level.

The feed device expediently has two parts which can be displaced relative to one another, each of which carries one of the rotary actuators. The rotary actuators for the inner pipe rod and the outer pipe rod are therefore of one another independent and self-employed. They can be moved axially against each other, while at the same time the inner pipe rod is axially displaced relative to the outer pipe rod. With the inner pipe linkage can lead or / and are not drilled in advance. When drilling in advance, the inner rod also serves as a guide of the outer rod, so that drilling in the correct direction is achieved.

When drilling into tensioned soil layers or starting the borehole below the groundwater horizon, in In connection with the flushing effected by the drilling device, the case that groundwater or mud occurs is conveyed under pressure through the drill pipe, so that the advance of a cylindrical borehole is not more is possible, but drives material randomly from the sides. Will get through the floor this way If material is withdrawn through the drill pipe, this leads to subsidence. To avoid this, takes place expediently a seal of the drill pipe.

For this purpose, the drilling tool can be the lower end of the Have outer pipe rods filling shaft part, which seals the opening cross section of the outer pipe and locks. A sealing element is preferably inserted in the vicinity of the front end of the drill pipe Inside wall used. When using such a drilling tool, the drill rod is always closed.

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ORIGINAL INSPECTED

In order to be able to close the drill rod if necessary, it is more advantageous Further development of the invention provides that a second shaft part with a smaller one is located above the shaft part Diameter is located and that the drilling tool by moving the inner pipe string in the outer pipe string is displaceable in such a way that either the thicker or the thinner shaft part is at the level of the sealing element is movable. By moving the inner pipe rod relative to the outer pipe rod, so on the front End of the drill string a sealing closure can be achieved.

Appropriately, ^ between the two rotary drives arranged a jacket surrounding the inner pipe rod, which is, for example, a flexible bellows can act. This jacket serves as a noise protection to dampen the sound emitted by the inner pipe rods.

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-SS-

The directions of rotation of the inner pipe rod and outer pipe rod are preferably opposite to one another. This improves the directional accuracy of the hole.

The feed device is an expedient development the invention controlled so that the inner pipe rod and the outer pipe rod advanced alternately so that by alternately leading the inner pipe rod and outer pipe rod a better Guiding of the outer pipe rod is achieved so that more precise drilling is possible.

In the following, some exemplary embodiments of the invention are explained in more detail with reference to the figures.

Show it:

Figure 1 is a side view of the drive device,

FIG. 2 shows a longitudinal section through the front part of the drill rod in a first embodiment,

Figure 3 is a longitudinal section through the front part of the

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Drill rods with sealed outer pipe with a ram tip as a drilling tool,

FIG. 4 shows an embodiment similar to that of FIG. 3, but with a lathe chisel as a drilling tool,

Figure 5 shows a further embodiment with flushing the drilling edge and

Figure 6 shows the embodiment of Figure 5, but with withdrawn drilling tool and sealed outer pipe rod.

The drill rod 10 exists in all of the exemplary embodiments from the outer pipe rod 11 and the coaxial therein running inner pipe rod 12. The rear end of the outer tubular rod 11 is connected to a rotary drive 13 according to FIG. The rotary drive 13 has a (not shown) hydraulic motor or pneumatic motor that drives a gear 14 with internal teeth. That Gear 14 is in engagement with a connecting pipe 15, the front end of which is screwed to the outer pipe rod 11 is. In the lateral surface of the connecting pipe 15 0 there is an opening 16 which, when turned, opens to a Annular groove 17 runs along inside the housing 18. the Annular groove 17 communicates with an ejection opening 19, so that the drilling mud flushed up through the outer pipe rod 11 through the opening 16 and the annular groove 17 reaches the ejection opening 19. By a seal 20, the passage between the inner pipe rod 12 and the connecting pipe 15 seals, it is prevented that the drilling mud on the inner pipe string 12 along to the rear got.

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The inner pipe rod assembly 12 leads through the first rotary drive 13 to the second rotary drive 21. The second rotary drive 21 drives the inner pipe rod assembly 12 in a rotational manner. For this purpose, the inner pipe rod 12 is over a connecting piece 23 screwed on a connecting pipe 24 which forms the rear end of the inner pipe rod assembly 12 and this connects to the second rotary drive.

The first rotary drive 13 is on the first part 25 of a Feed device 27 is attached, while the second rotary drive 21 is attached to the second part 26 of the feed device is appropriate. The two parts 25 and 26 are relative to one another by a piston-cylinder unit 28 moveable. They lie in one plane and their mutual distance can be changed by the piston-cylinder unit 28

The feed device 27 also has a chain drive, the chain 29 of which is attached to a shoulder 30 of the part 26 attacks. The endless chain 29 revolves around sprockets 31, 32, at least one of which is driven. By driving the chain 2 9, the assembly can

20_ the rotary drives 13, 21 pushed forward or back as a whole will.

There is an intermediate space between the two rotary drives 13 and 21, which is bridged by the inner pipe rod assembly 12 will. To avoid being in this gap

! 5 too strong sound radiation from the inner pipe rod occurs, an annular bellows 33 is provided, the ends of which at the rotary drives 13 and 21 are attached and which surrounds the otherwise exposed part of the inner pipe rod 12. When the piston-cylinder unit 28 is actuated, the distance between the rotary drives 13 changes and 21. As a result of its flexibility, the annular bellows 33 adapts to these changes in distance.

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ORIGINAL INSPECTED

The rotary drives 13 and 21 are independent of one another. The rotary drive 13 rotates the outer tubular rod 11, the lower end of which is shown in FIG. The second rotary drive 21 rotates the inner pipe rod assembly 12 _{; at the} front end of which, according to FIG. 2, the downhole hammer 22 striking a shaft of the drilling tool 34 is attached. The drilling tool 34 is inserted with its hexagonal shaft 35 into a hexagonal opening at the front end of the downhole hammer. The shaft 35 serves as an anvil for the hammer piston (not shown) and has a longitudinal groove 36 which is delimited at both ends and into which a pin 37, which is inserted transversely through the hammer housing 22 ', protrudes. In the area of the longitudinal groove 36, the pin 37 can move freely, so that the inner pipe rod 12 can be pulled up a little without the drilling tool 34 being carried along. The impact is transmitted to the drilling tool 34 via the front face of the shaft 35.

The body of the drilling tool 34 is connected to the hexagonal shaft 35 via a transverse shear pin 39. The drilling tool 34 has a guide cross 40 which is adapted to the inner diameter of the outer pipe rod 11 on, while the drill bits 41 protrude laterally and determine the total borehole width.

The hexagonal shaft 35 has an axial bore 42 which is connected to the outlet of the downhole hammer 22 stands. Drive or flushing medium (e.g. compressed air or hydraulic fluid) flows through the bore 42, which is supplied to the the front end of the drilling tool 34 emerges and together with the cuttings in the annular space between the outer pipe string 11 and the inner pipe rod 12 is flushed away.

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- -er -

While the drill bit 34 is advanced by rotating and hitting at the same time, the outer pipe rod is only rotated by the rotary drive 13 and not hit.

In the embodiment of Figure 3, the drilling tool is a tapered ram tip 44, which at its rear Part has a cylinder 45. The cylinder 45 rests against the inner wall of the outer tubular rod 11 and it has a circumferential sealing ring 46 so that the front end of the outer pipe rod through the Cylinder 45 and the sealing ring 46 is completely closed.

The inner pipe rod 12 is also used here to supply a drive or flushing agent to a downhole hammer 80, which is attached to the front end of the Innanrohrgestänges 12 The downhole hammer 80 strikes an axially displaceable hexagonal shaft 47, which is connected to the drilling tool 44 is connected. A shear pin 48 serves as a connecting element, which tears off as soon as the force with the the Drilling tool 44 is withdrawn, exceeds a certain limit. The drilling tool 44 also abuts here with a rear annular shoulder 49 against the front end of the outer tubular rod 11.

The embodiment of Figure 4 is essentially the same as that of Figure 3, so that the individual each other Corresponding parts are provided with the same reference numerals in both figures. The drilling tool is in Figure 4, however, no ram point, but a drill bit 44 '. While in the embodiment according to FIG the advance is carried out exclusively by hammering,

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_AH 2324392

it follows in the exemplary embodiment according to FIG. 4 by striking and turning at the same time. In both embodiments the lower end of the outer pipe string 11 is sealed so that neither water from the borehole soil material that is still under tension can escape through the drill rods. That way you will be training of cavities and subsidence as a result of the borehole driving avoided. The drive medium for the downhole hammer flows after leaving the outlet opening 81 on the hammer housing directly between the inner pipe rods and outer tubing rod 11 back without touching the bottom of the borehole to get.

In the embodiment of Figures 5 and 6, the lower end of the outer tubular rod 11 can optionally be sealed will. The drilling tool 50 has a rearwardly directed cylinder 51 which is inserted into a pipe section 52 on the lower end of the outer pipe rod is fitted. The pipe section 52 is of a pipe jacket 53 with radial Surrounding distance. The pipe jacket 53 extends over a cylindrical section 54 of the drill bit 50, see above that the drill bit together with the walls 52 and 53 includes a cavity 55, which via bores 56, the pass through the drill bit 50, with the borehole bottom 57 is in communication.

Through a central bore 58 of the drill bit 50 connected to the inner pipe rod 12, flushing agent is in the borehole pressed into it. The flushing agent flows to the bottom of the borehole according to the arrows shown 57 and from there as drilling mud back through the bores 56 into the space 55. The flushing agent thus arrives through the drill bit 50 directly to the borehole

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-Vt-

sole and is then also back through the drill bit discharged through from the bottom of the borehole.

The cylindrical wall 52 has openings 59 at its rear end. Behind these openings is in an annular groove a sealing ring 60 is arranged.

During normal flushing operation, the inner pipe string 12 is advanced together with the drill bit 50, as shown in FIG Figure 5 is shown. In this state, the cylinder 51 exposes the openings 59, so that the detergent with the cuttings directly from the borehole bottom 57 through the bores 56, the space 55 and the openings 59 in the Annular space between the inner drill pipe and outer drill pipe get and carried out at the rear end of the drill pipe can be.

If it turns out that the borehole is flushed out by the flushing agent, so that more cuttings are flushed away than has been drilled loose, then the flushing can be interrupted by pulling together the piston-cylinder unit 28 (Figure 1) the drill bit 50 is withdrawn until the cylinder 51 closes the openings 5 9 and on the sealing ring 60 rests. The drill hole can now be opened by turning the drill bit and, if necessary, hitting it at the same time can be driven on without flushing. The advance is carried out by the advance device 27 or by the force of the chain 29 (Figure 1).

Should the inner pipe rod be pulled out of the outer pipe rod as shown in Figure 6, then ruptures after the rear shoulder 61 of the drill bit 5O against the front end of the outer tube

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stänges is pushed off, the shear pin 62, while the openings 5 9 dux'ch the cylinder 51 are closed.

The hexagonal shaft 63, which is axially sliding within limits in a connected to the inner pipe rod 12 Pipe 64 is guided, transmits the axial blows and the rotary movement from the one attached to the inner pipe rod 12 Downhole hammer 83 on the drill bit 50. It connects through its longitudinal bores 84 the outlet of the downhole hammer 83 with the central bore 58 of the drill 2.

In the embodiment according to Figures 5 and 6 there is the advantage that the detergent is only applied directly to the Borehole bottom 57 emerges and is also discharged again directly from the borehole bottom without hitting the side wall of the borehole. In this way, lateral washouts of the borehole are avoided. Should Rinsing can still take place in loose soils by closing the openings 59 without detergent continue to be drilled. Even then, no groundwater or soil material is created by the outer pipe rods discharged when the groundwater or soil material in the soil is under pressure. When the openings 5 9 are closed, a second outlet can be opened on the downhole hammer, so that the drive medium after leaving the downhole hammer in the external drill pipe flows back.

While FIG. 5 shows the state during drilling with flushing, FIG. 6 shows the state after tearing off of the shear pin 62, i.e. after the lost drill bit 50 has been severed, which then remains in the borehole, pictured. Between these two states there is a

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NEN middle state in which the shear pin 62 is still is not torn off, but the openings 59 are closed by the cylinder 51. This last one Condition is not shown.

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eerse

it

Claims (11)

-κ - claims 1. Drilling device for overlay drilling, with an in an inner pipe rod running on the outer pipe rod, at the end of which a downhole hammer hitting a drilling tool is attached, and with one the inner pipe rod rotating rotary drive, thereby characterized in that an independent second rotary drive rotating the outer tubular rod (13) provided and the outer pipe rod (11) from the The inner pipe rod (12) is decoupled suddenly so that both rotary drives (13, 21) are connected to a driven front - Pushing device (27) are mounted and that the drilling tool (34, 44, 44 ', 50, 71, 77) is separable in the borehole lost drilling tool is. 2. Drilling device according to claim 1, characterized in that the feed device (27) has two relative has mutually displaceable parts (25, 26), each of which carries one of the rotary drives (13, 21). 3. Drilling device according to claim 1 or 2, characterized in that that the drilling tool (22) has a cylinder (45, 51) which sealingly closes the opening cross-section of the outer tube. 4. Drilling device according to claim 3, characterized in that the gap between the lower end of the outer pipe rod (11) and the cylinder (45, 51) is sealed by a sealing element (46, 60). 030061/0556 ORIGINAL INSPECTED 5. Drilling device according to claim 4, characterized in that there is a shaft part above the cylinder (51) (65) is located with a smaller diameter and that the drilling tool (50) by moving the inner pipe rod (12) in the outer pipe rod (11) in this way is displaceable that either the cylinder (51) or the thinner shaft part (65) to the level of the Sealing element (60) is movable. 6. Drilling device according to one of the preceding claims, characterized in that the drilling tool (34, 44, 44 ', 50) with a predetermined breaking element (39, 48, 62) is attached to the anvil part of the downhole hammer and one against the lower end of the outer pipe rod (11) has abutting shoulder (49, 61). 7. Drilling device according to claim 1, characterized in that that between the two rotary drives (13, 21) an axially expandable one surrounding the inner drill rod (12) Sheath (33) is provided. 8. Drilling device according to one of the preceding claims, characterized in that the drilling tool (50) has outlet openings for the outlet of a flushing agent on the bottom of the borehole (57) and on its end face discharge channels (56) for the discharge of flushing agent and Has cuttings from the borehole bottom, and that the discharge channels (56) at the rear end of the drill bit in a space between the walls (52, 53) of the double-walled outer tubular rod from its lower end (11) lead. 030051/0556 9. Drilling device according to one of the preceding claims, characterized in that the outer pipe rod has an annular partition (52) with at least one opening (59) which is in a first axial Position of the cylinder (51) closable and opened in a second axial position of the cylinder (51) is. 10. Drilling device according to one of the preceding claims, characterized in that the outer pipe rod (11) and the inner pipe rod (12) in opposite directions Directions of rotation are driven. 11. Drilling device according to one of the preceding claims, characterized in that the feed device (27) is controlled in such a way that the outer pipe rod (11) and the inner pipe rod (12) alternately be advanced. 030051/0556