Clamp assembly for clamping a drill string component

Abstract

The invention relates to a clamping head arrangement for clamping a drill string element with a clamping head base, at least one clamping jaw body which is radially adjustable on the clamping head base between a clamping position and a release position relative to the drill string element, and at least one adapter element on the clamping jaw body, wherein the adapter element is adapted to a shape of the drill string element to be clamped and is designed to rest against the drill string element in the clamping position and to clamp it.According to the invention, the adapter element is detachably arranged on the clamping jaw base body and can be locked by means of an actuable locking device, and the locking device has at least one locking element which is adjustable between a locking position in which the adapter element is locked and fixed to the clamping jaw base body, and a release position in which the adapter element is released and removable from the clamping jaw base body.

Description

[0001] The invention relates to a clamping head arrangement for clamping a drill string element, comprising a clamping head base, at least one clamping jaw body which is radially adjustable at the clamping head base between a clamping position and a release position relative to the drill string element, and at least one adapter element on the clamping jaw body, wherein the adapter element is adapted to a shape of the drill string element to be clamped and is designed to bear against the drill string element in the clamping position and to clamp it, according to the preamble of claim 1.

[0002] A known clamping head arrangement is described, for example, in EP 1 936 109 B1. In this known arrangement, a drill string element can be clamped and held by three clamping jaws arranged at 120° intervals. Such clamping head arrangements are used particularly on drilling rigs where the drill string is composed of several drill string elements, especially those bolted together. Particularly when an additional drill string element is bolted on or when a drill string element is loosened during withdrawal from the borehole, such clamping head arrangements can be used to hold the existing drill string, preventing it from slipping back into the borehole. The loosening and tightening of the bolted connection within the drill string is also an important aspect here, as the clamping jaws can transmit high torques via friction when clamped.Depending on the type of drilling device, such a chuck arrangement can also be axially or radially movable.

[0003] The clamping head assembly features clamping jaws with a contact surface that ensures the largest possible contact area between the clamping jaw and the outer circumference of the drill string. This allows for the highest possible adhesive and frictional forces, and thus the best possible holding force on the drill string.

[0004] When changing the diameter of the drill string, it is therefore common to replace the actual clamping jaws, which can also be called adapter elements, with other clamping jaws whose contour is adapted to the changed outer circumference of the drill string.

[0005] It is known to loosen the connecting devices on the clamping jaws, remove the existing clamping jaws, and replace them with new ones. The connecting devices are then re-closed, making the clamping head assembly ready for use again. These replacement operations must be performed manually and involve a considerable amount of time and effort. Such devices are known, for example, from EP 2 322 757 A2.

[0006] The invention is based on the Task The basis is to specify a chuck arrangement with which adaptation to modified drill string elements can be carried out efficiently.

[0007] The problem is solved according to the invention by a clamping head arrangement with the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

[0008] The clamping head arrangement according to the invention is characterized in that the adapter element is detachably arranged on the clamping jaw base body and can be locked by means of an actuable locking device, and that the locking device has at least one locking element which is adjustable between a locking position in which the adapter element is locked and fixed on the clamping jaw base body, and a release position in which the adapter element is released and removable from the clamping jaw base body.

[0009] A fundamental aspect of the invention is that the adapter element, which constitutes the actual clamping jaw, is detachably mounted on a clamping jaw base and locked by means of an actuated locking device. Complex connecting devices, particularly those comprising screws, are thus eliminated. Instead, an easy-to-use and preferably automatically or semi-automatically actuated locking device with a locking element is provided. The locking element can be adjusted between a locking position and a release position by a simple locking movement, in particular a linear or arc-shaped movement. The locking device on the clamping jaw base thus enables quick release and locking, and therefore efficient exchange of the adapter elements.

[0010] A preferred embodiment of the invention consists in the clamping head base being essentially cylindrical or tubular. The clamping head base constitutes a base body or frame on which the clamping jaw bases are mounted. The clamping head base can be annular or sleeve-shaped and encompass the drill string element on its outer surface. Alternatively or additionally, the clamping head base can also be rod-shaped or similarly designed, so that it can be arranged within a tubular drill string element. Depending on the design of the clamping head base, clamping can thus be performed on the outer surface of the drill string element and / or on the inner surface of the drill string element.

[0011] In a simple embodiment, it may suffice to have a single clamping jaw base body, which can be positioned onto the drill string element with the clamping jaw or adapter element. According to a further development of the invention, it is particularly advantageous to arrange several clamping jaw base bodies distributed around the circumference of the drill string element to be clamped. In particular, two, three, four, or any other suitable number of clamping jaw base bodies with corresponding adapter elements can be arranged in a plane distributed around the circumference of the drill string element. In particular, the adapter elements are arranged radially opposite each other so that counter-forces can cancel each other out.

[0012] According to a further embodiment of the invention, it is advantageous that at least one locking element is pre-tensioned by a pre-tensioning device and held in the locking position. Preferably, all locking elements of the clamping head assembly are held pre-tensioned in the locking position. This ensures fail-safe operation. The pre-tensioning device can, in particular, be a tension spring with which the locking element is held in the locking position by spring force. Thus, to release the adapter element, the locking element must be actively moved into the release position with force against the pre-tensioning device. After the force is removed, the locking element returns to the locking position.

[0013] Furthermore, it is preferred that the at least one locking element has an actuating section for adjusting the locking element from the locking position to the release position. In particular, the actuating section can be a pin or a bolt, which preferably projects beyond the clamping jaw body. By actuating the actuating section, in particular by applying a compressive force to the actuating section, the locking element can be adjusted from the locking position to the release position.

[0014] In particular, according to one embodiment of the invention, it is advantageous that at least one locking element is slidably mounted on or in a clamping jaw base body and that an actuating section of the locking element projects towards the clamping jaw base body in the locking position. The locking element can preferably be adjustably mounted on or in the clamping jaw base body in a corresponding receptacle. The actuating section of the locking element can preferably project out of the receptacle so that the actuating section can be easily actuated.

[0015] According to a further embodiment of the invention, it is preferred that the at least one clamping jaw base body is mounted to be axially displaceable and that a wedge slide mechanism is formed at the clamping head base, by which an axial movement of the at least one clamping jaw base body can be converted into a radial clamping movement. Guide rails directed obliquely to the longitudinal axis of the drill string can be arranged at the clamping head base, or the clamping head base can be conically shaped overall, so that an axial displacement of the clamping jaw base body in the longitudinal direction also results in a radial positioning and clamping movement of the clamping jaw base body.

[0016] According to a further development, it is particularly advantageous that at least one stop is arranged at the base of the clamping head, against which an actuating section of the locking element can be moved, wherein the locking element can be adjusted from its locking position to the release position. In particular, during an axial movement, the actuating element can project forward in the direction of movement, so that after a certain adjustment movement of the clamping jaw base body, the actuating element is pressed axially against a stop. The stop is arranged such that the actuating section does not come into contact with the stop during a normal axial clamping movement for clamping a drill string. Rather, this is only possible if no clamping of a drill string element is intended and, accordingly, no drill string is arranged in the clamping head assembly.The stop allows the locking element to be moved from the locked position to the release position via the actuating element. In this position, the unlocked adapter element can then be removed from the clamping jaw base and a new, adapted adapter element inserted. With this design, the actuator can be used for unlocking and locking, and in drilling operation, it is also used to perform the clamping movement.

[0017] A preferred embodiment of the invention consists in particular in the arrangement of an adjusting device, especially with at least one adjusting cylinder, with which the at least one clamping jaw base body can be adjusted. The adjusting device can in particular have one or more hydraulic cylinders, which are preferably aligned parallel to the longitudinal axis of the drill string element to be clamped.

[0018] Another advantageous embodiment of the invention consists in the adapter element having at least one retaining section which projects into a recess in the clamping jaw base body, and in the at least one retaining section being designed to cooperate with the at least one locking element of the clamping jaw base body to secure the adapter element to the clamping jaw base body by at least a positive locking mechanism. The securing can preferably be achieved not only by positive locking but also by frictional locking.

[0019] It is particularly advantageous that the retaining section has a retaining pin with a locking recess in which the locking element engages with a locking section to form a positive locking mechanism. The retaining section can, in particular, have a through hole or, preferably, an external recess, especially an annular recess, into which the locking element engages with at least one locking section in a positive locking manner. This ensures reliable retention of the adapter element on the clamping jaw base.

[0020] Furthermore, according to one embodiment of the invention, the locking element may have a release section which, in the release position, is arranged at the locking recess such that the adapter element with the retaining section can be removed from the clamping jaw base. The locking element may, in particular, be a pin- or bolt-shaped locking element in which the release section is formed by a recess. When this recess of the release section is moved into the area of ​​the locking recess of the retaining section of the adapter element, the positive locking mechanism can be released. In this release position, the adapter element with the retaining section can be detached from the clamping jaw base and removed.

[0021] The invention further comprises a drilling rig for creating a borehole, particularly in soil, with at least one drill string element, wherein the clamping head arrangement described above according to the invention is provided. With such a drilling rig, the advantages described above can be achieved, especially when a change of the drill string with a different outer diameter is required.

[0022] The invention is further described below with reference to preferred embodiments, which are shown schematically in the drawings. The drawings show: Fig. 1 a cross-sectional view through a clamping head arrangement according to the invention; Fig. 2 a perspective view of a clamping jaw base body with an inserted adapter element in the locking position; Fig. 3 a perspective view of the adapter element with the associated locking element in the locking position without the clamping jaw base body; Fig. 4 a perspective view of the adapter element and locking element accordingly Figure 3 , however, in a release position of the locking element; and Fig. 5 a perspective view of the clamping jaw base body accordingly Figure 2 when removing the adapter element in the release position.

[0023] A clamping head arrangement 10 according to the invention with a sleeve-shaped clamping head base 12 is shown schematically in Figure 1The clamping head assembly 10 can be rigidly attached to a partially indicated rotary drive 80 and, in particular, to a rotating driven output element 82 with a fitting with an external thread 84. The clamping head base 12 can thus rotate with the output element 82 of the rotary drive 80. A drill string with a corresponding internal thread can be screwed onto the external thread 84 of the output element 82. The drill string is arranged within the sleeve-shaped clamping head base 12 and in Figure 1 not shown.

[0024] A chuck slide 14 is axially displaceable on the outside of the sleeve-shaped chuck base 12. For axial displacement, an adjusting device 70 with one or more adjusting cylinders 72 can be arranged, as also shown schematically in Figure 1The actuating device 70 can be fixedly attached to a base body (not shown), such as a drilling rig, and can be stationary relative to the rotating drive element 82. An actuating element 74, which is connected to the axially movable clamping slide 14 via rotary bearings 76, can be moved by means of the at least one actuating cylinder 72. In this way, an axial actuating movement can be transmitted from the relatively stationary actuating device 70 to the clamping slide 14, which rotates about a longitudinal and / or rotary axis at the clamping head base 12.

[0025] On a front side of the clamping slide 14, one or more clamping jaw base bodies 20 can be connected to the clamping slide 14 by means of an annular holder 22. The holder 22 can be designed such that it creates an axially fixed connection with the at least one clamping jaw base body 20, but allows radial movement of the clamping jaw base body 20 with respect to the clamping head base 12 in relation to the longitudinal or rotational axis.

[0026] An outer surface of the clamping jaw base body 20 is inclined or conical, so that it forms a wedge slide mechanism 18 with a corresponding inclined or conical guide element 17, which is fixedly attached to the outer surface of the clamping head base 12. The wedge slide mechanism 18 is designed such that, during an axial feed movement of the clamping slide 14, the clamping jaw base body 20 is adjusted not only axially but also in a defined radial direction, in particular radially inwards.

[0027] Plate-like adapter elements 30, preferably arcuate on their inner surface and adapted to the drill string element to be clamped, are arranged on the radial inner surface of the clamping jaw base 20. The adapter elements 30 extend through window-like openings 16 in the clamping head base 12 from the clamping jaw base 20, which is attached to the radial outer surface, into the interior of the sleeve-shaped clamping head base 12. The resulting radial movement of the clamping jaw base 20 with the attached adapter elements 30 enables a radially force-fit clamping of a cylindrical drill string element arranged in the clamping head base 12. By resetting the clamping slide 14 using the adjusting device 70, the clamping jaw base 20 with the adapter element 30 is returned to its radial position, thereby releasing the clamping of the drill string element.

[0028] According to the invention, the adapter elements 30 are each detachably and replaceably held on the clamping jaw base body 20 by means of a locking device 40, wherein the locking device 40 has a bolt-like locking element 42 arranged parallel to the longitudinal or rotational axis with a pin-like actuating section 44 which projects axially towards an end face of the associated clamping jaw base body 20.

[0029] To release the locking device 40, the clamping jaw base body 20 can be moved to a forward end position, at which the actuating section 44 of the locking element 42 is pressed against an axial stop 60. The operation of the locking device 40 is described in more detail below in conjunction with the further figures.

[0030] In Figure 2A clamping jaw base body 20 is shown in an enlarged view. The clamping jaw base body 20 has a recess 26 into which the adapter element 30 with a retaining section 36 is appropriately inserted. Furthermore, Figure 2 It can be seen that the adapter element 30 has an arc-shaped clamping surface 32 on its upper side, the contour of which is adapted to an outer contour of a cylindrical drill string element to be clamped.

[0031] Within the clamping jaw base body 20, the locking device 40 is arranged with a bolt-shaped locking element 42. The locking element 42 is slidably mounted and held in a receiving bore in the clamping jaw base body 20 by means of a screwed mounting plate 24, wherein a pin-shaped actuating section 44 with a dome-shaped head projects definedly from the locking element 42 out of the clamping jaw base body 20.

[0032] The design and operation of the locking device 40 are described in connection with the schematic representations of the Figures 3 and 4 explained in more detail below. For the sake of clarity, only the adapter element 30 and the locking device 40 are shown, but not the surrounding clamping jaw base body 20.

[0033] This shows Figure 3The locking device 40 is in its locked position. The bolt-shaped locking element 42 is held in the locked position by a preload device 50, which, according to the illustrated embodiment, can be designed as a coil spring 52. A locking section 46 of the locking element 42 engages in an annular locking recess 38 of a retaining pin 37, which is formed on the underside of the retaining section 36 of the adapter element 30. The retaining pin 37 is received in a corresponding receiving bore within the clamping jaw base body 20. In this arrangement, the retaining pin 37 is thus positively locked in place by the locking section 46 engaging in the locking recess 38. In this locked position, the front actuating section 44 of the locking element 42 projects axially in a defined manner relative to the mounting plate 24 attached to the clamping jaw base body 20.

[0034] If the clamping jaw base body 20 is now adjusted according to the Figure 1 When moved axially against the stop 60, the actuating section 44 and thus the locking element 42 are pressed inwards into a release position, which is schematically shown in Figure 4 as shown. During this positioning movement, the larger diameter locking section 46 disengages from the locking recess 38. Furthermore, by moving the locking element 42 into the area of ​​the locking recess 38 on the retaining pin 37, a release section 48 of the locking element 42 is pushed in. The release section 48 has a smaller diameter than the adjacent locking section 46. The release section 48 is designed such that the retaining pin 37 is no longer positively locked, and thus the adapter element 30 can be pulled upwards out of the recess 26 on the clamping jaw base body 20, as shown, for example, in Figure 5As shown. In this release position, a new adapter element 30 can then be inserted into the clamping jaw base body 20, which preferably has a different arc-shaped contour of the clamping surface 32.

[0035] After inserting the new adapter element 30, the clamping jaw base body 20 can be adjusted accordingly. Figure 1 The adjusting device 70 pushes the bolt-shaped locking element 42 away from the stop 60 again. This adjusts the bolt-shaped locking element 42. The preload device 50, compressed in the release position, then returns the locking element 42 to the locking position with the coil spring 52. The locking element 42 then resumes its position accordingly. Figure 3 a.

[0036] In Figure 5 The schematic representation shows the removal of the adapter element 30 from the approximately rectangular recess 26 on the clamping jaw base body 20. Furthermore, the following is shown: Figure 5It is evident that in this release position accordingly Figure 4 the locking element 42 with the actuating section 44 is pressed into the receiving bore in the clamping jaw base body 20, wherein the actuating section 44 does not protrude from the front face of the clamping jaw base body 20 with the mounting plate 24.

Claims

1. Clamping head assembly for clamping a drill pipe element comprising - a clamping head base (12), - at least one clamping jaws base body (20) which is radially adjustable at the clamping head base (12) between a clamping position and a releasing position relative to the drill pipe element, and - at least one adapter element (30) on the clamping jaws base body (20), wherein the adapter element (30) is adapted to a shape of the drill pipe element to be clamped and is configured to abut and clamp the drill pipe element in the clamping position, characterized in that - the adapter element (30) is releasably arranged on the clamping jaws base body (20) and can be locked by means of an actuatable locking device (40), and - the locking device (40) comprises at least one latch element (42) adjustable between a locking position, in which the adapter element (32) is locked and secured to the clamping jaws base body (20), and a release position, in which the adapter element (30) is released and removable from the clamping jaws base body (20).

2. Clamping head assembly according to claim 1, characterized in that the clamping head base (12) is of substantially cylindrical or tubular design.

3. Clamping head assembly according to claim 1 or 2, characterized in that a plurality of clamping jaws base bodies (20) are arranged to be distributed over a circumference of the drill pipe element to be clamped.

4. Clamping head assembly according to any one of claims 1 to 3, characterized in that at least one latch element (42) is biased and retained in the locking position by a biasing device (50).

5. Clamping head assembly according to any one of claims 1 to 4, characterized in that the at least one latch element (42) comprises an actuating portion (44) for adjusting the latch element (42) from the locking position to the release position.

6. Clamping head assembly according to any one of claims 1 to 5, characterized in that the at least one latch element (42) is mounted displaceably on or in a clamping jaws base body (20), and in the locking position, an actuating portion (44) of the latch element (42) projects with respect to the clamping jaws base body (20).

7. Clamping head assembly according to any one of claims 1 to 6, characterized in that the at least one clamping jaws base body (20) is mounted to be axially displaceable, and a wedge gate valve mechanism (18) is formed on the clamping head base (12), by means of which mechanism an axial movement of the at least one clamping jaws base body (20) can be converted into a radial clamping movement.

8. Clamping head assembly according to any one of claims 1 to 7, characterized in that at least one stop (60) is arranged on the clamping head base (12), against which stop an actuating portion (42) of the latch element (42) is movable, wherein the latch element (42) is adjustable from its locking position to the release position.

9. Clamping head assembly according to any one of claims 1 to 8, characterized in that the adapter element (30) comprises at least one retaining portion (36) which projects into a recess (26) in the clamping jaws base body (20), and the at least one retaining portion (36) is configured to cooperate with the at least one latch element (42) of the clamping jaws base body (20) for at least positively securing the adapter element (30) to the clamping jaws base body (20).

10. Clamping head assembly according to claim 9, characterized in that the retaining portion (36) comprises a retaining pin (37) on which a locking recess (38) is formed, in which the latch element (42) engages with a latch portion (46) for positive locking in the locking position.

11. Clamping head assembly according to claim 10, characterized in that the latch element (42) comprises a release portion (48) which, in the release position, is arranged on the locking recess (38) in such a way that the adapter element (30) with the retaining portion (36) is removable from the clamping jaws base body (20).

12. Clamping head assembly according to any one of claims 1 to 11, characterized in that an adjusting device (70), in particular having at least one adjusting cylinder (77), is arranged, by means of which device the at least one clamping jaws base body (20) is adjustable.

13. Drilling apparatus for making a borehole, in particular in a ground, comprising at least one drill pipe element, characterized in that a clamping head assembly (10) according to any one of claims 1 to 12 is provided.

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