EP2851504A1 - Drill pipe gripper - Google Patents

Abstract

A drill pipe gripper having at least one collet chuck (20) with a push claw (24), which is linearly displaceable and can be extended for clamping a drill rod (5) or double drill pipe by means of a clamping cylinder (26), characterized in that in addition to the push claw (24) two pivoting jaws (30) are provided, which are pivotally mounted on a tong frame (22) opposite each other, and that the pivoting claws (30) are mechanically coupled to the linearly displaceable push claw (24), wherein upon extension of the push claw (24) the two pivoting claws (30) on the drill pipe (5) are pivotable.

Description

The invention relates to a drill pipe gripper with at least one collet with a push claw, which is mounted linearly displaceable and for tensioning a drill string by means of a clamping cylinder is extendable, according to the preamble of claim 1.

Such drill string grippers are used in particular in drilling rigs for earth or rock drilling, which approximately in the EP 1 832 710 B1 are described. These have a drilling device with drill carriage, along which a drill drive for drilling drill pipe elements of different diameters is slidably mounted. The drill string elements can be partially stacked in a magazine near the drilling device. By means of a drill string gripper, drill pipe elements can be transported from the magazine to the drilling device and back again. The drill string gripper can be automatically controlled or manually operated by a drill string manipulator.

For example, in special civil engineering such Gestängemanipulatoren be used with drill string grippers as work easier for handling single and double drill pipe. Frequently, the manipulators are mounted on a mini-excavator via a hydraulic turning or pivoting mechanism, driven by a free hydraulic circuit of the excavator and controlled electrically from the excavator's cab. With the degrees of freedom of a rotatable upper carriage of the excavator, the excavator boom and the pivot mechanism, the drill pipe can be separated from a storage position, picked up and swung into the drilling axis of the drill.

Usually modified linkage clamping devices of drilling tools are used for clamping the drill string. A generic drill string gripper, for example, goes from the DE 201 20 810 U1 out. The drill string elements are thereby clamped between a fixed stop and a displaceable clamping jaw, which is moved by means of a hydraulic cylinder. In this construction, it is disadvantageous that the position of the center axis of the tensioned drill pipe element changes when the diameter thereof changes. This can be compensated only by changing or moving the fixed stop and possibly a change in the jaw. This is particularly disadvantageous when a double rod with an outer tube and arranged therein, diameter smaller inner tube must be handled. Another disadvantage is the unfavorable for the recording of drill rods arrangement of the clamping cylinder. The lateral arrangement of a clamping cylinder requires a sufficient distance of the drill string elements in a drill pipe magazine, so that they can be gripped safely.

From the EP 1 832 710 B1 is a collet a drill pipe gripper with two pivoting clamping jaws known. With a change in the rod diameter results in a uniform displacement of the pivotable clamping jaws a certain displacement of the rod axis and that approximately perpendicular to the clamping direction. Especially when handling a Doppelbohrgestänges, in which the inner tube and the outer tube simultaneously seized from the drill pipe magazine and must be placed concentrically in the drilling axis of the drilling device for screwing with the drilled drill string, a positionally accurate gripping and inserting the Doppelbohrgestänges in the drilling axis for trouble-free operation essential.

The invention has for its object to provide a drill pipe gripper, with which a secure and accurate gripping of drill string elements is achieved with different diameters.

The object is achieved according to the invention by a drill pipe gripper with the features of claim 1. Preferred embodiments of the invention are indicated in the dependent claims.

The drill string gripper according to the invention is characterized in that in addition to the push claw two pivoting claws are provided, which are pivotally mounted on a tong frame opposite each other, and that the pivoting claws are mechanically coupled to the linearly movable push claw, wherein the extension of the push claw, the two pivoting claws on the Drill rods are too pivotable.

A basic idea of the invention is to simultaneously actuate two additional pivot claws with the method of the push claw. Thus, in a compact structure with preferably a single actuating cylinder, an actuation of three clamping jaws done. A cylindrical drill pipe can thus be gripped at three points around the circumference, whereby a secure and positionally accurate gripping a cylindrical drill pipe is supported. The contact points of the individual clamping jaws on the drill string are largely uniformly distributed around the circumference and preferably have an angular distance of 120 °.

This arrangement is particularly advantageous for gripping drill pipes with different outer diameters.

A secure gripping is further promoted according to a preferred embodiment of the invention in that at least two collets are provided, which are arranged along a gripper frame. Preferably, the two collets are arranged at the respective outer end of a rod-shaped connecting strut of the gripper frame. Depending on the size of the drill string element to be gripped, three or more collets may also be arranged along the gripper frame.

For a particularly stable embodiment according to a further embodiment of the invention, it is advantageous that the pivoting claws are connected to the push claw via a lever mechanism. By means of such a lever mechanism, the linear thrust movement of the thrust pawl can be translated into pivotal movement radially toward or away from the drill string member.

It is particularly advantageous that the lever mechanism has an intermediate lever, which is articulated on the one hand with the push claw and on the other hand with a pivoting claw via a pivot point. This will be a Lever mechanism achieved in the manner of a toggle lever, which allows a particularly good power transmission.

For a good power transmission, it is particularly expedient according to a further embodiment of the invention that the pivoting claws each have a claw portion for contacting the drill string and an actuating portion and that between the claw portion and the actuating portion a pivot bearing is arranged. The pivot bearing is thus located in a central region of the lever-shaped pivoting claw. The jaw portion and the actuating portion preferably extend in opposite directions away from the pivot bearing.

A particularly accurate position gripping is achieved according to a development of the invention in that the lever mechanism is designed so that the extension of the push claw the pivoting jaws and the thrust pawl are moved evenly on a longitudinal axis of the drill string to exciting. The current extension positions of the push claw and the two pivoting claws preferably always lie on a momentary contact circle, which always has the same center point. This center coincides with the application on a drill with the drilling axis. The circle of contact is to be understood as the circle on which the points of contact of the clamping claws lie with the outer surface of a cylindrical drill pipe to be clamped. With this arrangement, two or more collets on a drill string gripper can simultaneously engage telescoping drill string members of different bore diameters without requiring pre-adjustments to the chuck claws. There is thus the possibility that, with such a drill rod gripper, a single drill string element with a different outside diameter can then be gripped again using both collets.

Such uniform delivery of the push claw and the pivoting jaws can be achieved by a corresponding configuration of the lever mechanism. A particularly preferred embodiment according to the invention is that the axes of the pivot bearings of the pivoting jaws are arranged so that a connecting line between the two axes intersects the longitudinal axis of the drill string to be clamped. The connecting line provides the shortest connection between the two pivot axes of the pivot bearing of the opposite pivoting jaws.

For a good grip of drill string elements, it is advantageous according to a further embodiment of the invention that the clamp frame is fork-shaped with two forceps prongs and that the pivoting jaws are pivotable between a retracted position and a clamping position, wherein retracted in the retracted position, the pivoting claws substantially in a receiving space are, which is formed in the forceps prongs. Preferably, in the retracted position, the pivoting jaws are not or only slightly over against the surrounding forceps of the Zahngenrahmens, whereby a narrow design is achieved. This allows a retraction of the narrow collet in a rod magazine, in which the drill string elements are mounted only a small distance from each other. In addition, the swivel claws are well protected against external influences in the retracted position.

A development of the invention is that a Bohrgestängemanipulator is provided with a drill string gripper, which is arranged adjustable on a manipulator. The drill string gripper is configured according to the previous embodiments. The drill string gripper is in particular attached to a multi-axis manipulator arm with which the drill string gripper with several degrees of freedom in space is adjustable.

Furthermore, the invention comprises a drill with a drill pipe magazine for magazineing drill string elements and a drilling device with drill drive for drilling the drill string elements, wherein the above-described Bohrgestängemanipulator is provided. It can be provided in particular a drill, as in the aforementioned EP 1 832 710 B1 which is attributable to the Applicant. However, it may also be provided deviating drilling rigs with these features, these drills are preferably designed for earth and rock drilling.

A preferred embodiment is also that the drill for drilling a Doppelbohrgestänges formed with an outer drill pipe and a partially arranged therein, smaller diameter inner drill pipe and that the collets for simultaneous concentric gripping of the outer drill string and the inner drill string are arranged on the gripper frame. The at least two collets are arranged on the gripper frame in the gripping position parallel and at the same distance from the drill string axis. With this arrangement, it is possible with the drill rod gripper according to the invention to grasp drill string elements with different outside diameters in a positionally exact and concentric manner at the same time. This is the case in particular in the case of double drill pipe sections with an outer drill pipe, from which part an inner drill pipe having a smaller inner diameter arranged therein protrudes in part.

Fig. 1:

eine schematische perspektivische Ansicht eines erfindungsgemäßen Bohrgestängegreifers;

Fig. 2:

eine schematische Querschnittsansicht einer Spannzange des Bohrgestängegreifers von Fig. 1;

Fig. 3:

eine schematische Querschnittsansicht der Spannzange von Fig. 2 beim Greifen eines ersten Bohrgestänges; und

Fig. 4:

eine schematische Querschnittsansicht der Spannzange von Fig. 2 und Fig. 3 beim Spannen eines zweiten, Durchmesser kleineren Bohrgestänges.

The invention will be described below with reference to a preferred embodiment, which is shown schematically in the drawings. In the drawings show:

Fig. 1:

a schematic perspective view of a drill pipe gripper according to the invention;

Fig. 2:

a schematic cross-sectional view of a collet of the drill string gripper of Fig. 1 ;

3:

a schematic cross-sectional view of the collet of Fig. 2 when gripping a first drill pipe; and

4:

a schematic cross-sectional view of the collet of Fig. 2 and Fig. 3 when tensioning a second, smaller diameter drill string.

A drill pipe gripper 10 according to the invention Fig. 1 has a gripper frame 12, with which the drill string gripper 10 is attached to a only partially shown and schematically indicated manipulator arm 52 of a Bohrgestängemanipulators 50. By means of the manipulator arm 52 partially shown, the drill string gripper 10 can be moved, in particular to transport drill string elements from a drill pipe magazine to a drilling device and back again.

On the gripper frame 12, a transverse strut 14 is formed, attached at its two outer ends in each case a collet 20 for gripping the drill string element are. The two collets 20 are preferably identical and according to the illustrated embodiment. The collet 20 in this case has a fork-shaped forceps frame 22, which is formed from two frame plates 21 which are fixedly connected to one another via spacer elements 25. Within the clamp frame 22, a clamping cylinder 26 is arranged in a rear region, which is usually designed as a hydraulic cylinder. With the clamping cylinder 26, a push claw 24 is driven linearly displaceable within the clamp frame 22. Mechanically coupled to the push claw 24 are two pivotally mounted pivoting jaws 30, which are arranged within a receiving space 44 in the two forceps tines 23 of the fork-shaped forceps frame 22. For a reliable gripping a drill string 20 respectively grooved contact plates 32 are attached to the push claw 24 and the two pivoting jaws 30 of a collet.

The operation of the collets 20 of a drill string gripper 10 according to the invention will be described below in connection with FIGS. 2 to 4 explained. It is in Fig. 2 a normal position of the collet 20 shown, in which the push claw 24 and the two pivoting claws 30 are arranged in their respective retreat position. In this retraction position, the push claw 24 and the pivot claws 30 are each retracted into the receiving space 44, which is formed in the collet frame 22 between the two frame plates 21. The push claw 24 and the pivot claws 30 are not beyond an outer contour of the fork-shaped forceps frame 22 out. Overall, such a narrow structure of the collet 20 is given, whereby a gripping even closely spaced drill pipe elements is made possible.

According to Fig. 3 the gripping of a first diameter larger drill string 5 is shown with a longitudinal axis 3. For this purpose, a cylinder piston 27 of the clamping cylinder 26 is extended until the attached to the cylinder piston 27 thrust pawl 24 an outer periphery of the drill string 5 contacted.

On the outer sides of the plate-shaped push claw 24, an intermediate lever 28 is articulated in each case. At the opposite end of the intermediate lever 28 of this is pivotally connected via an articulation point 34 with an actuating portion 38 of the lever-shaped pivoting claw 30. The two pivoting claws 30 are respectively about a pivot bearing 40 about an axis 42 pivotally mounted on the forceps frame 22. The pivot bearing 40 is arranged approximately centrally between the actuating portion 38 and a claw portion 36 of the pivoting jaw 30. By the linear extension of the push claw 24 by means of the clamping cylinder 26, a pressure is exerted on the pivoting claws 30 via the articulated intermediate lever 28, through which the claw portion 36 is pivoted about the pivot bearing 40 in the direction of the longitudinal axis 3 of the drill string 5.

By this extension of the push claw 24 and the pivoting claws 30 from the retraction position in the forceps frame 22, the clamping jaws each reach the clamping position, at which the three clamping jaws distributed over the circumference of the drill pipe 5 abut against this.

This simultaneous multiple contacting of the pawl 24 and the pivoting claws 30 on the drill pipe 5 is independent of the diameter of the drill pipe 5, as shown in FIG Fig. 4 can be clearly seen. Here, the articulation of the pivoting claws 30 via a lever mechanism with the push claw 24 is designed so that a concentric gripping of the drill string 5 is made possible regardless of the outer diameter of the drill pipe 5. This is achieved in the illustrated embodiment in that the longitudinal axis 3 of the drill string 5 to be clamped intersects the direct connection line which extends between the axes 42 of the opposing pivot bearings 40 of the two pivoting claws 30. The in the FIGS. 2 to 4 Toggle mechanism shown with an intermediate lever 28 allows a tensioning of a drill string 5 with a relatively large contact pressure of the clamping jaws, so that a safe and even with changing outer diameters of the drill string 5 positionally accurate gripping is achieved.

With this embodiment according to the invention, a drill string gripper 10 can be provided with two or more identically designed collets 20, which can grip drill pipe 5 with a wide variety of outside diameters without conversion measures.

Claims (11)

A drill pipe gripper having at least one collet chuck (20) with a push claw (24) which is mounted in a linearly displaceable manner and can be extended by a clamping cylinder (26) for clamping a drill pipe (5),
characterized,
in that, in addition to the push claw (24), two pivot claws (30) are provided, which are pivotably mounted on a clamp frame (22) opposite one another, and
in that the swiveling claws (30) are mechanically coupled to the linearly displaceable push claw (24), the two swiveling claws (30) being pivotable towards the drill pipe (5) during extension of the push claw (24). A drill pipe gripper according to claim 1,
characterized,
in that at least two collets (20) are provided, which are arranged along a gripper frame (12). A drill pipe gripper according to claim 1 or 2,
characterized,
in that the swivel claws (30) are connected to the push claw (24) via a lever mechanism. A drill pipe gripper according to claim 3,
characterized,
in that the lever mechanism has an intermediate lever (28) which is articulated on the one hand to the push claw (24) and on the other hand to a pivoting claw (24) via an articulation point (34). A drill pipe gripper according to any one of claims 1 to 4,
characterized,
that the pivoting claws (30) each have a claw portion (36) for contacting the drill string (5) and an actuating portion (38), and
in that a pivot bearing (40) is arranged between the claw section (36) and the actuating section (38). A drill pipe gripper according to any one of claims 3 to 5,
characterized,
in that the lever mechanism is designed such that, on extension of the push claw (24), the pivot claws (30) and the push claw (24) can be moved uniformly along a longitudinal axis (3) of the drill pipe (5) to be clamped. A drill pipe gripper according to claim 5 or 6,
characterized,
in that the axes (42) of the pivot bearings (40) of the swiveling claws (30) are arranged so that a connecting line between the two axes (42) intersects the longitudinal axis (3) of the drill string (5) to be clamped. A drill pipe gripper according to any one of claims 5 to 7,
characterized,
in that the forceps frame (22) is fork-shaped with two forceps tines (23) and
that the pivoting jaws (30) are pivotable between a retracted position and a clamping position, wherein the pivotal jaw (30) are retracted substantially into a receiving space (44) in the retracted position, which in the gripper prongs (23) is formed. Bohrgestängemanipulator with a drill string gripper (10), which is arranged on a manipulator arm (52) adjustable,
characterized,
in that a drill pipe gripper (10) according to one of claims 1 to 8 is provided. Drill with a drill pipe magazine for storing drill pipe elements and a drilling device with drill drive for drilling out the drill pipe elements,
characterized,
that a Bohrgestängemanipulator (50) is provided as claimed in claim. 9 Drilling device according to claim 10,
characterized,
that this is designed for drilling a Doppelbohrgestänges with an outer drill pipe and a partially arranged therein, smaller-diameter inner drill pipe and
in that the collets (20) are arranged on the gripper frame (12) for simultaneous concentric gripping of the outer drill pipe and the inner drill pipe.

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