TELESCOPIC DRILL RODS, ESPECIALLY KELLY RODS

Description

[0001] The invention relates to a telescopic drill rod, in particular a Kelly rod, with at least two rod elements which are designed and arranged to be axially telescopic relative to one another, wherein axially extending and mutually directed driver bars for torque transmission between the rod elements are arranged on at least one circumferential side of the tubular rod elements, according to the preamble of claim 1.

[0002] Telescopic drill rods, also known as Kelly rods or Kelly bars, have been used for many decades to create boreholes in the ground. Such a drill rod enables the suspension of a drilling tool from a support cable, with torque being transmitted via the telescopic drill rod from a drill drive on a drilling rig. The drill drive is ring-shaped, with the drill rod extending through a ring-shaped drive wheel. The torque can be transmitted via axially extending drive bars on the outside of the outer Kelly rod element, whereby the drill rod can be axially displaced relative to the rotary drive. Axial forces can also be transmitted via locking pockets.By arranging one or more inner Kelly rod elements in a telescopic manner with additional drive bars, even greater drilling depths can be achieved by extending the drill rod accordingly. The torque is transferred from the outer Kelly rod element to the next adjacent inner Kelly rod element via axial drive bars.

[0003] For functional reasons, the individual rod elements are mounted with a certain amount of play in relation to each other in order to ensure sufficient mobility.

[0004] Such telescopic drill rods are typically used for discontinuous drilling, for example with a drilling bucket or auger, here referred to as the drilling tool. Once the drilling tool is filled with excavated soil material after a drilling step, the drilling tool is withdrawn from the borehole, and the telescopic drill rod is retracted. The drilling tool is moved outside the borehole to an emptying position, typically pivoted, at which the auger is emptied by a reversing rotary movement, known as shaking. A drilling bucket is emptied by opening a hinged bottom. For reliable emptying of the drilling bucket, particularly with cohesive soil material, it is common to assist emptying by shaking.

[0005] Particularly during such a vibration-based emptying process, the telescopic drill rod can emit considerable noise. During a vibration movement, the individual tubular drill rod elements strike each other with their axial stop bars.

[0006] Noise-intensive work is particularly undesirable during construction work within cities. Such work may be prohibited above a certain noise level, or time restrictions may apply.

[0007] To reduce sound radiation from a Kelly rod, it is known, for example, from DE 40 41 303 C2, to equip it with sound-absorbing insulation elements in cavities and along the perimeter. However, due to functional reasons, such soft insulation elements can only be placed in specific locations, thus not providing comprehensive sound insulation.

[0008] The invention is based on the TaskThe aim is to provide a telescopic drill rod with which a further reduction in noise during operation can be achieved.

[0009] The object is achieved by a telescopic drill rod having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

[0010] According to the invention, the telescopic drill rod is characterized in that at least one first coupling element is arranged on the first rod element and at least one second coupling element is arranged on the second rod element, which are axially coupled in an axially retracted state of the rod elements and are in engagement with one another in such a way that a circumferential force is generated between the two coupling elements in the circumferential direction of the rod elements, with which circumferential force adjacent driving strips of the rod elements are pressed against one another and held in contact with one another.

[0011] It is a finding of the invention that a significant portion of the noise generated during drilling with a telescopic drill rod is attributable to the preferably metallic rod elements colliding with one another when the telescopic drill rod is being handled, particularly when it is being emptied by vibration. Significant noise is generated particularly in the axially retracted state when the telescopic drill rods are located outside the borehole and thus outside the surrounding ground. Arranging and handling a conventional telescopic drill rod above the ground surface results in particularly intense sound transmission to the environment, resulting in undesirable noise. Noise reduction is also achieved when the rod elements are made of a different material, such as carbon fiber reinforced plastic (CFRP), rather than metal.

[0012] A basic idea of ​​the invention can be seen in the fact that the at least two rod elements of a telescopic drill rod are clamped against one another in the circumferential direction or subjected to force in an axially retracted state such that, in particular, the adjacent driver bars are either pressed and held against one another in the circumferential direction or are kept at a distance. This ensures that the rod elements, which are guided with a certain amount of play due to operation, are held in a fixed position relative to one another and thus can no longer or hardly at all strike against one another, especially during reversing rotation. In this way, a large part of the noise generation can be avoided from the outset, with sound radiation correspondingly reduced.

[0013] A preferred embodiment of the invention consists in that at least one wedge-shaped cam and / or a cam receptacle is formed on the second coupling element, that at least one cam receptacle with a corresponding wedge surface is formed on the first corresponding coupling element, and that when the coupling elements are axially pushed together, the at least one wedge-shaped cam comes into contact with the wedge surface of the cam receptacle to generate the circumferential force. When the rod elements of the drill string are axially retracted or pushed together, at least one or more opposing coupling elements engage with one another, wherein the rod elements, and in particular adjacent driver bars of the rod elements, are pressed against one another in the circumferential direction and held under tension in this position.The resulting holding force for positioning the rod elements relative to each other can be selected so that the individual rod elements are no longer, or hardly at all, able to collide with each other during further handling of the drill rod. The coupling elements can thus ensure a force-locking and / or form-locking of the rod elements. The cams and cam receivers can also be interchanged or arranged alternately.

[0014] The coupling elements form a wedge-slide mechanism, so to speak, that generates a desired pressure force in the circumferential direction. Preferably, the coupling elements can be arranged vertically relative to one another in such a way that the individual coupling elements are pressed axially or vertically against one another by the gravitational force of at least one of the linkage elements. By appropriately designing the cams and / or wedge surfaces, the weight or contact force is redirected or converted into a desired circumferential force or torque.

[0015] According to a further development of the invention, a particularly good fixation of the linkage elements to one another can be achieved by at least one coupling element, preferably both corresponding coupling elements, being annular. This allows for force distribution along the circumference. The annular coupling elements, with their at least one cam and / or cam receptacles, can each be formed as a single piece.

[0016] It is particularly advantageous that a plurality of wedge-shaped cams and / or cam receptacles are formed on the at least one annular coupling element. The annular coupling elements with the plurality of cams or cam receptacles can, in particular, be arranged uniformly and / or alternately distributed along the annular shape. This allows particularly uniform forces to be generated, distributed over the circumference, for pressing the rod elements in the circumferential direction.

[0017] According to a further embodiment of the invention, it is preferred that an inner rod element is provided, at the upper end of which a holding device for holding and suspending the drill rod is arranged, and at the lower end of which a support for at least one outer rod element is arranged. At least one upwardly directed coupling element is arranged on the support, and a downwardly directed coupling element is formed on a lower region of the at least one outer rod element. When the rod elements are axially retracted, the downwardly directed coupling element rests on the upwardly directed coupling element of the inner rod element and engages with it.When the telescopic drill rod is suspended by a cable via the inner rod element, the at least one outer, tubular rod element, in the retracted state, can rest on the at least one coupling element of the inner rod element with its own coupling element. The contact force of the at least one outer rod element can be used efficiently to generate the desired circumferential force through the interaction of the two coupling elements.

[0018] According to a further development of the invention, it is particularly advantageous that a plurality of annular coupling elements, which have different ring diameters and are arranged concentrically to one another, are arranged on the support of the inner rod element. The number of annular coupling elements on the inner rod element corresponds to the number of tubular outer rod elements of the telescopic drill rod. Preferably, one, two or three, or in individual cases even several, outer rod elements can be arranged concentrically, which together with the inner rod element form the telescopic drill rod. The outer rod elements each have a larger diameter from the inside to the outside. The same applies to the respectively assigned coupling elements.Preferably, the plurality of coupling elements on the inner rod element can also be formed in one piece, for example together on an annular body.

[0019] According to one embodiment of the invention, it is preferred that several annular external rod elements are provided, each of which has different tube diameters and comprises a downwardly directed annular coupling element at its lower end. The downwardly directed coupling elements have different diameters and are arranged concentrically to one another. In particular, a concentric arrangement of the annular coupling elements allows for the most uniform force distribution possible in the telescopic drill rod.

[0020] According to a further variant of the invention, it is advantageous that a connecting device, in particular a square pin, for attaching a drilling tool is formed at a lower end of the drill rod, in particular of the inner rod element, below the support. A connection formed with a square pin represents a standard connection, so that different drilling tools, such as a drilling bucket, auger, or a displacement drill, can be detachably attached. In principle, other connecting devices can also be provided on the drill rod.

[0021] To further reduce sound radiation, according to a further development of the invention, it is preferred that an axial damping element be arranged between the support and the connecting device. The damping element can be made, in particular, of an elastic rubber or plastic material. This protects both the drill rod and the drilling tool during operation. By further preventing metal parts from colliding, sound radiation during operation can also be further reduced.

[0022] For efficient operation with the drill rod according to the invention, it is advantageous according to a further embodiment of the invention that a radially outwardly projecting annular collar is formed at an upper end of an outer rod element for attachment to a drill drive. In principle, a damping element can also be arranged on the annular collar, in particular on its underside, and / or on an opposite annular support surface of the drill drive.

[0023] To reduce sound radiation, insulating or damping materials can also be arranged on other surfaces of the telescopic drill rod or in unused cavities.

[0024] The invention further comprises a drilling device for creating a borehole in the ground, comprising a carrier unit and a mast attached thereto and a rotary drive, wherein the drilling device is further developed in that a telescopic drill rod according to the invention, in particular as described above, is arranged on the mast.

[0025] The invention also includes a method for creating a borehole in the ground with a drilling tool, wherein the drilling tool is held on a telescopic drill rod according to the invention and / or a drilling device according to the invention is used.

[0026] With such a drilling rig or such a method, the advantages described above when using a telescopic drill rod can be achieved.

[0027] A preferred embodiment of the method according to the invention consists in that, at least when a drilling tool is withdrawn from the ground, the telescopic drill rod is retracted in such a way that at least two rod elements with corresponding coupling elements are retracted axially relative to one another. In the axially retracted state of the rod elements, these are axially coupled and engage with one another in such a way that a circumferential force is generated between the coupling elements in the circumferential direction of the rod elements, with which adjacent driver bars of the rod elements are pressed against one another and held in contact with one another or at a distance from one another. This can counteract a bell-like impact of the metal parts of the drill rod, which are mounted with play relative to one another, and the resulting noise generation.

[0028] According to a further development of the invention, particularly quiet operation can be achieved by executing a vibrating movement of the drill rod around the longitudinal axis of the rod when the rod elements are retracted to empty the drilling tool. The vibrating movement can be generated, in particular, by a reversing rotational movement exerted by the drill drive. The forces generated in the circumferential direction by the coupling elements for holding and bracing the rod elements are, in particular, adjusted such that they are greater than the inertial forces exerted on the individual rod elements by the vibrating movement.Thus, when performing a shaking movement, which can be used, for example, to empty a drilling bucket or auger, the rod elements are held together at least in a force-locking manner and repeated impact of the metallic rod elements and the associated noise generation are avoided.

[0029] The invention will be further described below with reference to preferred embodiments, which are schematically illustrated in the drawings. In the drawings: Fig. 1 shows a schematic side view of a drilling rig with a drill rod according to the invention; Fig. 2 shows an enlarged detailed view of a lower end region of a drill rod according to the invention; Fig. 3 shows a perspective detailed view of the coupling elements on a drill rod according to the invention; and Fig. 4 shows a detailed view of the coupling elements of a drill rod according to the invention in a retracted state.

[0030] A drilling device 10 with a telescopic drill rod 30 according to the invention is shown in Fig. 1 A carrier unit 11 of the drilling rig 10 can preferably have a movable undercarriage 12, which in the example shown is designed as a crawler chassis, and a superstructure 13 rotatably mounted thereon. A mast 16, which is essentially vertical during operation, can be adjustably articulated via a linkage mechanism 14, which can have articulated levers and actuators.

[0031] On a front side of the mast 16, a linear mast guide 19 is formed, along which a carriage 17 with a drilling drive 18 is displaceably mounted and can be moved vertically by means of a feed winch 22.

[0032] A support cable 28 can preferably be guided over a mast head of the mast 16, with the telescopic drill rod 30 suspended by a holding device 32 at the free end of the support cable 28. The drill rod 30 is guided through the ring-shaped drill drive 18, with a drilling tool 20 being detachably attached to the lower end of the drill rod 30. The drilling tool 20 is designed, for example, as a drilling auger, which is surrounded by a cylindrical cage with holes. An annular collar 70 can be arranged at an upper end region of the drill rod 30, with which the drill rod 30 can be placed on the drill drive.

[0033] The design and operation of the telescopic drill rod 30 are further described in the Figures 2 to 4shown and described with reference thereto. The telescopic drill rod 30 according to the invention has a first inner rod element 40, on the outside of which outer driver bars 42 extending in the longitudinal or axial direction are arranged in a basically known manner. A support 44 with an annular first coupling element 45 arranged thereon can be formed on a lower region of the inner rod element 40. At least one upwardly open cam receptacle 48 with a beveled wedge surface 49 is formed on the first coupling element 45 of the inner rod element 40. In the illustrated embodiment, two first coupling elements 45 can be provided, which are arranged concentrically to one another and lie one inside the other. The two first coupling elements 45 can be formed separately or on a common annular body with a correspondingly enlarged annular width.

[0034] At the lower end of the inner rod element 40, a connecting device 36 is arranged, which can be designed with a square pin 37 for the detachable attachment of a drilling tool 20. A damping element 38 can be arranged between the support 44 and the connecting device 36, wherein the support 44 is mounted with the at least one first coupling element 45 so that it can be axially displaced and dampened relative to the connecting device 36.

[0035] In the circumferential direction adjacent to the inner rod element 40, a first outer rod element 50 is arranged, as can be clearly seen from Fig. 3 The first outer linkage element 50 has outer driver bars 52 and inner driver bars 54, each of which is designed to transmit torque between the individual linkage elements 40, 50, 60.

[0036] On an underside of the first outer rod element 50, a second coupling element 55 is formed with at least one downwardly directed cam 56, which is designed to engage in a cam receptacle of a further first coupling element 45, not shown in the figures, on the inner rod element 40.

[0037] Again, a second outer linkage element 60 can be arranged circumferentially adjacent to the first outer linkage element 50, which also has outer driver bars 62 and inner driver bars 64 for torque transmission. On the underside of the second outer linkage element 60, an annular second coupling element 65 is arranged with at least one downwardly directed cam 66, which is designed to engage the upwardly open cam receptacle 48 of the first coupling element 45 of the inner linkage element 40.

[0038] In Fig. 4A detailed view of the drill rod 30 is shown in a retracted state, in which the downward-facing cam 66 of the second coupling element 65 of the outer rod element 60 is retracted into the cam receptacle 48 on the first coupling element 45 of the inner rod element 40. During axial retraction, an inclined wedge surface 69 of the cam 66 engages the wedge surface 49 of the cam receptacle 48 in such a way that a clockwise force, indicated by an arrow, is exerted on the outer rod element 60 relative to the inner rod element 40. The circumferential force thus generated presses the adjacent driver bars 42, 52, 54, and 64 against one another in the circumferential direction and is held in this state by a force-locking connection.This largely prevents undesired collision of the metallic parts during further handling of the drill rod 30, in particular when performing a shaking movement.

Claims

1. A telescopic drilling rod, in particular a Kelly rod, having at least two rod elements (40, 50, 60), which are configured and arranged to be axially telescopic with one another, wherein axially extending driver strips (42, 52, 54, 64) directed towards one another are arranged on at least one circumferential side of the tubular rod elements (40, 50, 60), for torque transmission between the rod elements (40, 50, 60), characterised in that at least one first coupling element (45) is arranged on a first rod element (40), and at least one second coupling element (55, 65) is arranged on a second rod element (50, 60), which are axially coupled in an axially retracted state of the rod elements (40, 50, 60) and engage with one another in such a way that a circumferential force is generated between the two coupling elements (45, 55, 65) in the circumferential direction of the rod elements (40, 50, 60), with which mutually adjacent driver strips (42, 52, 54, 64) of the rod elements (40, 50, 60) are pressed against one another and held in contact with one another.

2. The telescopic drilling rod according to claim 1, characterised in that at least one wedge-shaped cam (56, 66) and / or a cam receptacle (48) is designed on the second coupling element (55, 65), in that at least one cam receptacle (48) with a corresponding wedge surface (49) or a cam (56, 66) is designed on the first corresponding coupling element (45), and in that the at least one wedge-shaped cam (56, 66) comes into contact with the wedge surface (49) of the cam receptacle (48) to generate the circumferential force when the coupling elements (45, 55, 65) are slid axially together.

3. The telescopic drilling rod according to claim 1 or 2, characterised in that at least one coupling element (40, 50, 60), preferably all coupling elements (40, 50, 60) corresponding to one another, are designed annularly.

4. The telescopic drilling rod according to claim 3, characterised in that a plurality of wedge-shaped cams (56, 66) and / or cam receptacles (49) are designed on the at least one annularly designed coupling element (40, 50, 60).

5. The telescopic drilling rod according to any one of claims 1 to 4, characterised in that an inner rod element (40) is provided, at the upper end of which there is arranged a holding device (32) for holding and suspending the drilling rod (30) and at the lower end of which there is arranged a support (44) for at least one outer rod element (50, 60), in that at least one upwardly directed coupling element (45) is arranged on the support (44), and in that a downwardly directed coupling element (55, 65) is designed on a lower region of the at least one outer rod element (50, 60) and in an axially retracted state of the rod elements (40, 50, 60) rests on the upwardly directed coupling element (45) of the inner rod element (40) and is in engagement therewith.

6. The telescopic drilling rod according to claim 5, characterised in that a plurality of annular coupling elements (45) is arranged on the support (44) of the inner rod element (40) and have different ring diameters and are arranged concentrically with one another.

7. The telescopic drilling rod according to claim 5 or 6, characterised in that a plurality of annular outer rod elements (50, 60) are provided, which have different pipe diameters and at their lower end in each case have a downwardly directed annular coupling element (55, 65), wherein the downwardly directed coupling elements (55, 65) have different diameters and are arranged concentrically with one another.

8. The telescopic drilling rod according to any one of claims 1 to 7, characterised in that a connection device (36), in particular a square pin (37), is designed at a lower end of the drilling rod (10), in particular of the inner rod element (40), beneath the support (44), for attaching a drilling tool (20).

9. The telescopic drilling rod according to claim 8, characterised in that an axial damping element (38) is arranged between the support (44) and the connection device (36).

10. The telescopic drilling rod according to any one of claims 1 to 9, characterised in that a radially outwardly protruding annular collar (70) for fitting on a drill drive (18) is designed at an upper end of an outer rod element (50, 60).

11. A drill rig for making a borehole in the ground, comprising a carrier unit (11) and a mast (16) attached thereto and a drill drive (18), characterised in that a telescopic drilling rod (30) according to any one of claims 1 to 10 is arranged on the mast (16).

12. A method for making a borehole in the ground using a drilling tool (20), characterised in that the drilling tool (20) is held on a telescopic drilling rod (30) according to any one of claims 1 to 10 and / or a drill rig (10) according to claim 11 is used.

13. The method according to claim 12, characterised in that at least, when withdrawing a drilling tool (20) from the ground, the telescopic drilling rod (30) is retracted in such a way, wherein at least two rod elements (40, 50, 60) with corresponding coupling elements (45, 55, 65) are retracted axially to one another, wherein, in the axially retracted state of the rod elements (40, 50, 60), these are axially coupled and engaged with one another in such a way that a circumferential force is generated between the coupling elements (45, 55, 65) in the circumferential direction of the rod elements (40, 50, 60), by means of which mutually adjacent driver strips (42, 52, 54, 62, 64) of the rod elements (40, 50, 60) are pressed against one another and are held in contact with one another.

14. The method according to claim 13, characterised in that in the retracted state of the rod elements (40, 50, 60), to empty the drilling tool (20), a shaking movement of the drilling rod (30) is executed about a rod longitudinal axis.