Drill drive assembly

Abstract

The invention relates to a drilling drive arrangement for a double drill rod assembly with an outer rod assembly and an inner rod assembly, which is arranged at least in sections within the outer rod assembly along a drilling axis, with an outer rod assembly drive for rotatingly driving the outer rod assembly, a first carrier unit on which the outer rod assembly drive is arranged, an inner rod assembly drive for rotatingly driving the inner rod assembly, wherein the inner rod assembly drive is arranged axially offset from the outer rod assembly drive, a second carrier unit on which the inner rod assembly drive is arranged, and a displacement device with which the inner rod assembly drive with the second carrier unit is axially displaceable relative to the outer rod assembly drive with the first carrier unit.According to the invention, it is provided that the displacement device has at least one guide rod with a fixed piston section, wherein the guide rod is fixedly attached either to the first carrier unit or to the second carrier unit, that on the at least one guide rod at least one actuating cylinder housing with a piston cavity is mounted and guided in a slide-like manner, in which the piston section of the guide rod is arranged and which can be pressurized with a pressurized fluid in order to move the actuating cylinder housing along the guide rod, and that the second carrier unit or the first carrier unit, to which the at least one guide rod is not fixedly attached, is attached to the actuating cylinder housing.

Description

[0001] The invention relates to a drilling drive arrangement for a double drill rod assembly with an outer rod assembly and an inner rod assembly, which is arranged at least in sections within the outer rod assembly along a drilling axis, with an outer rod assembly drive for rotating the outer rod assembly, a first carrier unit on which the outer rod assembly drive is arranged, an inner rod assembly drive for rotating the inner rod assembly, wherein the inner rod assembly drive is arranged axially offset from the outer rod assembly drive, a second carrier unit on which the inner rod assembly drive is arranged, and a displacement device with which the inner rod assembly drive with the second carrier unit is axially displaceable relative to the outer rod assembly drive with the first carrier unit, according to the preamble of claim 1.

[0002] For drilling in overburden and unstable soils, drilling rigs or drill drive assemblies are often used which have independent drives for the rotary movement of a protective or outer tube and an inner drill rod. These drill drive assemblies for such double drill rods are often referred to as double-head drilling rigs. In double-head drilling rigs, it is advantageous if the inner drill rod can be moved longitudinally of the drilling axis relative to the outer tubular drill rod, i.e. the protective tube. This not only facilitates screwing processes during rod installation and removal, but also offers other drilling-related advantages. For example, the drill bit at the end of the drill rod can be set to lead or lag behind the ring bit on the protective tube, depending on the soil type encountered during drilling.

[0003] In a double-head drilling rig, the drive for the outer protective tube is usually the "front" drive facing the borehole. The drive for the inner drill rod is the "rear" drive located behind it. A rod-shaped rod adapter for the drill rod is threaded through the hollow shaft of the front drive so that both connecting connections, for example, in the form of threads, for both the outer protective tube and the inner drill rod are still located "in front of" or "below" the "front" drive, respectively, to ensure easy accessibility when changing the rod.

[0004] The function of the relative displacement of the rear drive is achieved by mounting this drive on its own carriage, which can also be called a tandem carriage, which can be displaced relative to the base carriage on which the front drive is mounted in the direction of the drilling axis. An actuating element, usually consisting of at least one hydraulic cylinder, is used for this purpose. This actuating element is attached to the base carriage on one side and to the tandem carriage on the other. Such generic drilling drive arrangements with such a displacement device for relative displacement of the drives are known, for example, from documents DE 19930504 B4, DE 3503893 C1, DE 8509145 U1, DE 19732479 C1, or DE 202007001858 U1.

[0005] In a special form, which emerges from DE 10005475 A1, the actuator in the form of a hydraulic cylinder is on the one hand firmly connected to the base carriage, and on the other hand rotatably connected to the rotary union, the so-called flushing head, of the rear drive for the drill rod.

[0006] Another known design according to EP 0860580 B1 is that the drive for the drill rod has a carriage that, like the carriage of the front drive, is guided directly on a carriage. In this case, there is an adjusting element that can position the rear carriage relative to the front carriage. The feed system of the drill carriage is only attached to the front carriage.

[0007] In all known designs, the displacement function and the linear guide function of the tandem slide as a support unit for the rear drive are separated, and a second slide (tandem slide) is usually required. With this design, the mountings for the actuator, the linear guides, and the tandem slide, or at least the guide surfaces, must be manufactured and mounted on the rear rotary drive.

[0008] The invention is based on the Task The aim is to provide a drilling drive arrangement for a double drill rod which has a particularly efficient and compact design.

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

[0010] In the drill drive arrangement according to the invention, it is provided that the displacement device has at least one guide rod with a fixed piston section, wherein the guide rod is fixedly attached either to the first carrier unit or to the second carrier unit, that at least one actuating cylinder housing with a piston cavity is mounted and guided in a slide-like manner on the at least one guide rod, in which the piston section of the guide rod is arranged and which can be acted upon by a pressurized fluid in order to move the actuating cylinder housing along the guide rod, wherein the guide rod extends through the piston cavity, and that the second carrier unit or the first carrier unit, to which the at least one guide rod is not fixedly attached, is attached to the actuating cylinder housing.

[0011] The inventive design results in a significant simplification of the structure of the drill drive arrangement. A functional separation between guide and actuating element is, so to speak, eliminated. According to the invention, the displacement device comprises at least one guide rod with a piston section arranged thereon. The guide rod is attached either to the first support unit for the outer rod drive or to the second support unit for the inner rod drive. Instead of a separate tandem slide, an actuating cylinder housing with an inner piston cavity is mounted in a slide-like manner directly on the at least one guide rod. The piston section on the guide rod lies in the inner piston cavity of the actuating cylinder housing and thus directly forms an actuating element for the displacement device.By applying a pressurized fluid to the inner piston cavity of the actuating cylinder housing, the fluid can be moved, preferably in reverse, along the guide rod. The other support unit, which is not directly connected to the piston rod, is attached to the actuating cylinder housing.

[0012] In addition to the considerable structural simplification, the geometric accuracy, in particular the alignment of the axes of the inner rod drive and the outer rod drive, can be significantly improved, for example because the play of the neck bushings of an actuating cylinder can be tolerated much more closely than the play that a tandem slide would have to have compared to a basic slide.

[0013] The arrangement according to the invention can, in particular, comprise a so-called synchronous cylinder, which can also be referred to as a synchronous or steering cylinder. Technically speaking, this is a double-acting, hydraulic linear drive with a cylinder housing and a guide or piston rod that protrudes from the housing, sealed on both sides. The at least one synchronous cylinder provided can preferably have fastening options for the rotary drive, in particular for the inner rod drive, on the actuating cylinder housing. Likewise, fastening elements for fastening to the other support unit, in particular the first support unit for the outer rod drive, can be arranged at the free ends of the guide rod.

[0014] A preferred embodiment of the invention comprises at least two guide rods, each with an actuating cylinder housing, wherein the actuating cylinder housings are preferably rigidly connected to one another. The arrangement of two or more guide rods increases the guidance accuracy of the linear guide thus formed. Furthermore, an actuating cylinder housing can be arranged on each additional guide rod, so that correspondingly higher actuating forces can be generated for displacing the support units with the drives relative to one another. In principle, guide rods or other linear guides could also be arranged to increase guidance accuracy without an additional actuating cylinder housing.

[0015] According to a further development of the invention, it is advantageous that the at least one guide rod is fixedly attached to the first carrier unit with the outer rod drive, wherein the second carrier unit with the inner rod drive is mounted and guided displaceably along the at least one guide rod.

[0016] The first support unit with the outer rod drive can itself be designed as a carriage, in particular as a so-called base carriage, which can be guided along a mast or a carriage. The second support unit with the inner rod drive can be mounted displaceably relative to the first support unit. The second support unit is thus mounted displaceably relative to the first support unit with the outer rod drive. Thus, the inner rod can be axially displaced relative to the outer rod, the so-called protective tube, according to a predetermined travel path.

[0017] In principle, the at least one guide rod can be fixedly arranged on one side of the one support unit, so that the guide rod has a free end. According to one embodiment of the invention, a particularly stable arrangement is achieved in that the at least one guide rod has two opposite end regions, which are either both fastened to the first support unit or both to the second support unit. Thus, the two ends of a guide rod are each fastened to the first support unit or the second support unit. This results in a particularly stable arrangement of the guide rod on one of the support units, so that the other support unit, which can be moved relative to it, can be guided in a very precise manner.

[0018] The guide rod can have any suitable cross-section, in particular a square or polygonal cross-section. The guide rod is particularly preferably cylindrical with a circular cross-section.

[0019] A further advantageous embodiment of the invention is that the piston section of the guide rod divides the piston chamber in the actuating cylinder housing into two separate pressure chambers, each of which can be pressurized with a pressurized fluid for reversible displacement of the actuating cylinder housing on the guide rod. The pressurized fluid can be, for example, compressed air or preferably hydraulic oil. Appropriate connections and lines for the pressurized fluid are arranged on the actuating cylinder housing so that the individual pressure chambers can be specifically pressurized with or vented with the pressurized fluid via a suitable control and / or valve device. In this way, a desired position of the actuating cylinder housing along the guide rod can be set and maintained.

[0020] According to a further development of the invention, particularly good guiding properties are achieved in that the actuating cylinder housing has at least one, preferably two, guide sections, which are configured to match an outer diameter of the guide rod to form a linear guide. The at least one guide section can be configured, in particular, as a guide or sliding bushing that is guided to fit the guide rod. Particularly when two or more guide rods are arranged, a very precise, virtually play-free linear guide can be efficiently achieved.

[0021] The at least one guide section can be formed, in particular, from a suitable lubricious material, such as bronze or brass. If necessary, one or more sealing rings can also be formed on the at least one guide section, so that the piston cavity of the actuating cylinder housing is pressure-tightly sealed to the outside.

[0022] According to a further development of the invention, it is preferred that the inner rod drive and / or the outer rod drive comprise one or more drive motors and / or an impact unit. Preferably, one or two drives can be arranged. With an impact unit, which can be arranged in particular on the rear inner rod drive, additional impact pulses for percussive rotary drilling can be applied.

[0023] It is particularly advantageous for the at least one drive motor to be designed as an electric motor, a compressed air-driven motor, or a hydraulic motor. In principle, other drive motors can also be provided that can generate a rotating drive for the inner rod or the outer rod. These motors enable a particularly compact design.

[0024] The drives can be designed as a direct drive for directly driving the respective rods. According to one embodiment of the invention, it is particularly expedient for the inner rod drive and / or the outer rod drive to comprise one or more gears. The gear can, in particular, be designed as a reduction gear, which allows for increased torque to be achieved at a reduced speed.

[0025] The drilling drive arrangement according to the invention can in principle be used wherever a double drill rod with outer rod and inner rod is driven in rotation.

[0026] According to one embodiment, the invention comprises a drilling rig with a carrier and a mast or carriage, along which a drilling drive assembly for a double drill rod is displaceably mounted, wherein the drilling drive assembly is designed according to the invention. By using the drilling assembly according to the invention in a drilling rig, in particular for earth and rock drilling, the previously described advantages can be achieved with the drilling rig.

[0027] The carrier device can be equipped with a mast that is essentially vertical during operation or with a carriage that is relatively freely adjustable in space. A carriage can also be used to adjust the drilling axis to a position that is essentially horizontal or inclined to it. The inner and outer rods are preferably arranged coaxially with each other.

[0028] In principle, the drilling rig can be designed as a stationary drilling rig. According to a further development, it is particularly preferred that the carrier device be designed to be movable, in particular with a crawler chassis.

[0029] The invention will be further explained below with reference to preferred embodiments, which are schematically illustrated in the drawings. In the drawings: Fig. 1 is a side view of a drill drive assembly according to the invention in a first operating state; Fig. 2 is a plan view of the drill drive assembly of Fig. 1from above; Fig. 3 a side view of a drill drive arrangement according to the invention in a second operating state; Fig. 4 a plan view of the drill drive arrangement of Fig. 3 from above; and Fig. 5 an enlarged cross-sectional view of a displacement device of the drill drive arrangement according to the Figures 1 to 4 .

[0030] According to the Figures 1 and 2 A drilling drive arrangement 10 according to the invention has a first carrier unit 20, which can be designed in the manner of a carriage with a lower carriage guide 22 for guiding along a linear guide on a mast or a carriage of a carrier device.

[0031] An outer rod drive 30 is attached to the first support unit 20 for rotating a tubular outer rod 20, which is only partially indicated, around a drilling axis 1. The drill rod drive 30 can be arranged as shown in the Figures 1 and 2two drive motors 32 which jointly drive a first gear 34, via which a torque is transmitted to the outer rod 2 via a corresponding rod connection.

[0032] Arranged coaxially with the tubular outer rod 2 is an inner rod 4, which extends through the outer rod drive 30 to an inner rod drive 50 located behind it in the direction of the drilling axis 1. The inner rod drive 50 can preferably also have two drive motors 52, which drive the inner rod 4 in rotation about the drilling axis 1 via a common second gear 54. The direction of rotation of the outer rod 2 and the inner rod 4 can be the same or different.

[0033] For an axial displacement of the inner rod drive 50 with the inner rod 4 relative to the outer rod drive 30 with the outer rod 2, according to the illustrated embodiment, the inner rod drive 50 is arranged on a second carrier unit 40, which can be displaced via a displacement device 60 in the direction of the drilling axis 1 relative to the first carrier unit 20 with the inner rod drive 50.

[0034] In the Figures 1 and 2 the drilling drive arrangement 10 is shown in a first operating state in which the inner rod drive 50 with the second carrier unit 40 is moved into a rear position in which the inner rod drive 50 is further spaced from the outer rod drive 30.

[0035] In the illustrated embodiment, the displacement device 60 comprises two guide rods 62 arranged parallel to one another, each of which is fastened by its two free ends to the slide-like first support unit 20. A cylindrical or box-shaped actuating cylinder housing 70 is displaceably mounted on each guide rod 62, with the two actuating cylinder housings 70 being firmly connected to one another via the second support unit 40 with the internal rod drive 50.

[0036] With the displacement device 60, the second carrier unit 40 with the inner rod drive 50 can be axially displaced on the inner rod 4. In the Figures 3 and 4 the drill drive arrangement 10 is shown in a second operating state, in which the inner rod drive 50 with the second carrier unit 40 is moved from the rear position according to the Figures 1 and 2has been moved into a forward position in which the inner rod drive 50 is arranged near the outer rod drive 30.

[0037] The structure and operation of an actuating cylinder housing 70 of the displacement device 60 are described in more detail in connection with Fig. 3 explained.

[0038] According to Fig. 3the actuating cylinder housing 70 has an inner piston cavity 72 through which the guide rod 62 extends axially. In a central region of the guide rod 62, a piston section 64 is formed, which in the illustrated embodiment is formed from two disc-shaped regions with two radial seals 66 arranged between them. The piston section 64 divides the piston cavity 72 in the actuating cylinder housing 70 into two pressure-tightly separated pressure chambers 73, 74. By means of schematically indicated pressure fluid lines 80, the individual pressure chambers 73, 74 can be specifically pressurized with a pressure fluid, in particular a hydraulic oil, or vented, in order to thereby effect a targeted displacement of the actuating cylinder housing 70 relative to the guide rod 62 and thus of the internal rod drive 50.

[0039] In addition to the actual displacement function, the actuating cylinder housing 70 also fulfills a guide function. In the illustrated embodiment, a first guide section 75 and a second guide section 76 are formed, each of which can have a guide bushing 79. The inner openings of the guide bushings 79, together with the outer circumference of the preferably cylindrical guide rod 62, can form a sliding fit and thus a linear guide. One or more sealing rings 78 can be arranged on each of the two guide sections 75, 76 in order to pressure-tightly seal the adjacent pressure chamber 73, 74 against the outside atmosphere. The displacement device 60 designed in this way can also be referred to as a synchronous cylinder, which performs both a displacement function and a linear guide function.

[0040] At the free ends of the respective guide rod 62, fastening eyes can be formed, for example, as fastening elements 68, in order to fasten the guide rod 62 to the corresponding carrier unit, here the first carrier unit 20, on both sides.

[0041] Compared to a conventional actuating device on a drill drive assembly for a double drill rod, the drill drive assembly 10 according to the invention allows for a more compact and overall lighter design. This saves space and weight, which, particularly with regard to a conventional arrangement of the drill drive assembly 10 on a mast or carriage, reduces the risk of tipping and enables an increase in the maximum achievable drilling depth.

Claims

1. Drilling drive arrangement for a double drill rod assembly with an outer rod assembly (2) and an inner rod assembly (4), which is arranged at least partially within the outer rod assembly (2) along a drilling axis (1), with - an outer rod assembly drive (30) for rotating the outer rod assembly (2), - a first support unit (20) on which the outer rod assembly drive (30) is arranged, - an inner rod assembly drive (50) for rotating the inner rod assembly (4), wherein the inner rod assembly drive (50) is arranged axially offset from the outer rod assembly drive (30), - a second support unit (40) on which the inner rod assembly drive (50) is arranged, and - a displacement device (60) with which the inner rod assembly drive (50) with the second support unit (40) is axially displaceable relative to the outer rod assembly drive (30) with the first support unit (20), characterized by - thatthe displacement device (60) has at least one guide rod (62) with a fixed piston section (64), wherein the guide rod (62) is fixedly attached either to the first carrier unit (20) or to the second carrier unit (40), - that on the at least one guide rod (62) at least one actuating cylinder housing (70) with a piston cavity (72) is mounted and guided in a slide-like manner, in which the piston section (64) of the guide rod (62) is arranged and which can be acted upon with a pressure fluid for displacing the actuating cylinder housing (70) along the guide rod (62), wherein the guide rod (62) extends through the piston cavity (72), and - that the second carrier unit (40) or the first carrier unit (20) is arranged on the actuating cylinder housing (70), to which the at least one guide rod (62) is not fixedly attached.

2. Drill drive arrangement according to claim 1, characterized by that at least two guide rods (62) are arranged, each with an actuating cylinder housing (70), wherein the actuating cylinder housings (70) are preferably firmly connected to one another.

3. Drill drive arrangement according to claim 1 or 2, characterized by that the at least one guide rod (62) is fixedly attached to the first carrier unit (20) with the outer rod drive (30), wherein the second carrier unit (40) with the inner rod drive (50) is mounted and guided displaceably along the at least one guide rod (62).

4. Drill drive arrangement according to one of claims 1 to 3, characterized by that the at least one guide rod (62) has two opposite end regions, which are either both attached to the first support unit (20) or both attached to the second support unit (40).

5. Drill drive arrangement according to one of claims 1 to 4, characterized by that the piston section (64) of the guide rod (62) divides the piston cavity (72) in the actuating cylinder housing (70) into two separate pressure chambers (73, 74), which can each be pressurized with a pressure fluid for the reversible displacement of the actuating cylinder housing (70) on the guide rod (62).

6. Drill drive arrangement according to one of claims 1 to 5, characterized by that the actuating cylinder housing (70) has at least one, preferably two guide sections (75, 76) which are designed to match an outer diameter of the guide rod (62) to form a linear guide.

7. Drill drive arrangement according to one of claims 1 to 6, characterized by that the outer rod drive (30) and / or the inner rod drive (50) comprises one or more drive motors (32, 52) and / or an impact unit.

8. Drill drive arrangement according to claim 7, characterized by thatthe at least one drive motor (32, 52) is designed as an electric motor, a compressed air-operated motor or a hydraulic motor.

9. Drill drive arrangement according to one of claims 1 to 8, characterized by that the outer rod drive (30) and / or the inner rod drive (50) comprises one or more gears (34, 54).

10. Drilling rig with a carrier and a mast or carriage, along which a drilling drive arrangement (10) for a double drill rod is slidably mounted, characterized by that the drill drive arrangement (10) is designed according to one of claims 1 to 9.

11. Drilling device according to claim 10, characterized by that the carrier device is designed to be movable, in particular with a crawler chassis.

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