EP2299049B1 - Coupling for drilling rods - Google Patents

Description

The invention relates to a plug-in coupling for a drill pipe, as well as a one or more such plug-in couplings exhibiting drill pipe.

A variety of methods and apparatus have been developed in the art for introducing horizontal wells into the soil. In these holes can then be withdrawn simultaneously or subsequently new pipes or pipes for example, the water or electricity supply.

Horizontal drilling devices are known from the prior art in which a drill pipe with a drilling head fastened to its front end is introduced into the soil via a drive device arranged in a starting excavation pit or on the earth's surface. By means of the drive device in this case a thrust and torque are transmitted to the drill head in order to drive this within the soil. It is also known to provide this drive device additionally with a percussion drive, which can be activated if necessary, when the drill head in the ground encounters an obstacle, such as a boulder. The generation of impact pulses and their transmission via the drill pipe to the drill head, the obstacle should be destroyed, so that subsequently can be used again in the normal, ie pushing and rotating drilling operation. In these horizontal drilling rigs are used regularly drill pipe whose sections (rod sections) are connected to each other via screw. The screwing of the individual rod sections can be done automatically in a corresponding embodiment of the drive device. Advantages associated with the use of threaded drill pipe connections for the described horizontal boring devices are the relatively inexpensive manufacture, the play-free transmission of both compressive forces (In particular, impact pulses) and tensile forces as well as torques in at least one direction of rotation. The main disadvantage, however, is that a transmission of (high) torques in the direction of release of the screw is not possible. In addition, a considerable amount of time is associated with the screwing of the individual rod sections even in an automated implementation.

From the field of trenchless pipe laying rods are known whose rod bosses are connected to each other by means of plug-in couplings. These rods are thereby starting from a target shaft (for a pipe to be laid) by means of a pulling device, which can also work pushing through an already created hole or to be rehabilitated sewer pipe and after reaching a start shaft via an adapter with the pipe to be laid connected. By means of the pulling device, the pipe is then drawn into the bore or the sewer pipe. Although such linkage must transmit high tensile forces, but only low compressive forces (the initial sliding from the target into the starting shaft) and no impact pulses and torques. For this reason, for the horizontal drilling devices described in the introduction, in which the drill string is driven by a arranged on the surface of the drive unit both sliding and rotating and partially under the action of shock pulses through the soil, so far no drill pipe used, which are connected via plug-in couplings.

CH 223 733 A discloses a rock drill with replaceable rock drill head. The rock drill head is provided with a conical approach. In addition, an extension drill pipe is described, which is open on both sides and whose bore merges at the ends in conical extensions, which serve for receiving detachable associated components, in particular for inserting the conical approach of the rock drill head. The rock drill thus has a plug-in coupling with at least two coupling elements, wherein the coupling elements have a first corresponding coupling surface pair, namely the conical projection and the conical expansion, wherein the coupling surface pair is designed to be tapered, ie conical here. When a loading of the plug-in coupling with compressive forces a backlash-free clamping is generated.

Based on this prior art, the present invention seeks to provide an existing of a variety of rod sections drill pipe in which the rod sections can be easily connected to each other and ensures a secure transmission of torque and high pressure forces.

This object is achieved by the subject matters of the independent claims. Advantageous embodiments of the invention are the subject of the respective dependent claims and will become apparent from the following description of the invention.

An inventive drill string consists of a plurality of rod sections, wherein the individual rod sections are at least partially connected to each other via a plug-in coupling designed according to the invention.

An inventive plug-in coupling for such a drill string has at least two coupling elements, wherein the coupling elements form at least a first corresponding pair of coupling surfaces, which is tapered, so that when a loading of the plug-in coupling with pressure forces a (possible) clearance-free clamping is generated. The clamp generated according to the invention between the two coupling elements of the plug-in coupling ensures a direct and loss-free as possible transmission of compressive forces and impact pulses over the existing drill string consisting of several rod sections.

Preferably, the plug-in coupling of the invention has a relatively small taper angle (i.e., the angle that the tapered surface makes with the longitudinal axis of the respective coupling element). This is preferably not more than 10 ° and more preferably not more than 5 ° (based on the longitudinal axes of the coupling elements). Particularly preferably, the two coupling elements of the plug-in coupling can be provided with corresponding conical sections.

In the plug-in coupling according to the invention, the coupling elements have at least a second corresponding pair of coupling surfaces via which a torque can be transmitted in the engaged state of the plug-in coupling. This allows the use of a drill pipe according to the invention for drilling methods in which a torque is to be transmitted from a drive device to a drill head at the front end of the drill pipe, as may be required, for example, to realize a control function of the drilling device.

For this purpose, the drill pipe can be provided at its front end with an oblique control surface are generated by the transverse (to the longitudinal axis of the drill string) directed forces that lead to a lateral deflection of the front end of the drill string. This results in a stationary, i. non-rotating driven drill pipe an arcuate course of the bore. A reversal can be achieved by rotating the drill string manually or by means of a corresponding (rotary) drive by a defined angle about its longitudinal axis, so that the oblique control surface is realigned. A quasi-straight bore course can in principle be achieved by continuously rotating the drill string so that the transversely directed (deflection) forces are compensated in the course of one revolution of the front end of the drill string.

In particular, if a drilling device e.g. can be controlled by an inclined control surface at the front end of the drill string, it may be advantageous to provide one of the front rod sections and in particular the foremost rod section of the drill pipe according to the invention with a position sensor, whereby the position of the corresponding rod assembly can be determined. This allows the determination and control of the exact course of the bore.

To transmit a torque or to form the second corresponding coupling surface pair is provided to provide one of the coupling elements with a mandrel which is flattened at least on one side to form a coupling surface and in the engaged state of the plug-in coupling in a recess of second coupling element in which in turn a corresponding coupling surface is formed, engages.

In a further preferred embodiment of the plug-in coupling according to the invention, the coupling elements have at least a third corresponding pair of coupling surfaces via which tensile forces can be transmitted in the engaged state of the plug-in coupling. Tensile forces can be exerted on the drill pipe, for example, to retract it after the creation of a hole. If the tensile forces are so great that thereby the frictional connection of the first corresponding pair of coupling surfaces of the or the plug-in couplings is released, a complete release of the individual plug-in coupling (s) is prevented by the third coupling surface pair. A complete release of one of the plug-in couplings of the drill string could cause the separated part of the drill pipe would have to be recovered by excavation.

In a further preferred embodiment of the plug-in coupling according to the invention can be provided that between two relative positions of the coupling elements, in which either the first coupling surface pair or the third pair of coupling surfaces abutting each other, a displacement is provided. This displacement can be provided to make the plug-in detachable.

In this embodiment of the plug-in coupling according to the invention can also be provided that in the two relative positions of the two coupling elements to each other, the second pair of coupling surfaces abutting each other, so that both during the propulsion and during the retraction of the drill string (ie, if tensile forces are applied thereto) a transmission a torque on the plug-in coupling is possible.

Further preferably, the plug-in coupling can be designed so that it is detachable by the two coupling elements are first pivoted to each other and then one of the coupling elements is rotated by a defined angle about its own longitudinal axis. By this sequence of relative movements of the two coupling elements to each other can be ruled out that the plug-in coupling according to the invention dissolves during normal drilling operation unintentionally.

In order to solve the stucco coupling according to the invention also manually, for example, when a rod section of the drill string after creating the hole at a destination (eg a target excavation) has arrived, preferably means may be provided with which the clamping of the first coupling surface pair are released again can. For this purpose, a transverse opening can be provided in one of the coupling elements, into which e.g. a wedge can be driven, by which a force for releasing the clamping is exerted on the corresponding other coupling element.

A further preferred embodiment of the drill pipe according to the invention provides that the rod sections are at least partially tubular. As a result, on the one hand, the weight of the individual rod sections of the drill string can be reduced. In addition, in a corresponding embodiment of the rod sections, in particular with respect to the outer diameter and the wall thickness of the tubular sections, a drill pipe to be generated, which can transmit high impact pulses, tensile forces and torques, but at the same time is so flexible that reaches a good steerability in the ground can be.

The rod sections of the drill string may further include a marker, e.g. a one-sided flattening in a drill pipe with round cross-section, have, by means of which the roll angle can be determined visually or automatically within the soil.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig. 1:

eine erfindungsgemäßes Bohrgestänge in einer ersten Kupplungsstellung in einer geschnitten Seitenansicht; und

Fig. 2:

die Steckkupplung gemäß Fig. 1 in einer zweiten Kupplungsstellung in einer geschnitten Draufsicht.

In the drawings shows:

Fig. 1:

an inventive drill string in a first coupling position in a sectional side view; and

Fig. 2:

the plug-in coupling according to Fig. 1 in a second coupling position in a cut plan view.

The Fig. 1 shows two rod sections 1 of a drill string according to the invention, which are tubular with a circular cross-section. The rod sections 1 each have two coupling elements on the end, which form a plug-in coupling according to the invention. About this plug-in coupling the two rod sections 1 can be connected to each other, the transmission of tensile and compressive forces and a torque in both directions is possible.

One of the coupling elements on each rod section 1 is formed as a plug-in part 2, which is inserted into the other coupling element of the adjacent rod section 1 formed as a receiving part 3.

The coupling element designed as a plug-in part 2 has a shaft 4 which has a circular cross-section. This shaft 4 merges into a locking shoulder 5, which is likewise produced starting from a circular cross-section, which projects beyond the diameter of the shaft 4, but which has been flattened on two opposite sides by the milling of plane surfaces 6. Furthermore, the locking shoulder 5 is tapered in conical shape with a small taper angle of about 5 ° (see. Fig. 2 ). Starting from the locking shoulder 5, the male part merges into a mandrel 7 which, like the locking shoulder 5, has been produced starting from a circular cross-section with a diameter smaller than that of the shaft 4 by milling plane surfaces 8 on two opposite sides , The plane surfaces 6 of the locking portion 5 are rotated by 90 ° (with respect to the longitudinal axis of the respective rod assembly) to the flat surfaces 8 of the mandrel 7.

• Eine zentrale, im Querschnitt kreisförmige Bohrung 9 dient im eingekuppelten Zustand des Steckkupplung der Aufnahme des Verriegelungsabsatzes 5 sowie jeweils eines Abschnitts des Schafts 4 und des Dorns 7 des Steckteils 2 (vgl. Fig. 2). Ein Abschnitt dieser zentralen Bohrung 9 ist - wie der Verriegelungsabschnitt 5 des Steckteils 2 - sich konisch verjüngend ausgebildet. Die konischen Flächen des Verriegefungsabsatzes 5 des Steckteils 2 sowie der zentralen Bohrung 9 des Aufnahmeteils 3 bilden zusammen ein (erstes) Kupplungsflächenpaar aus, das bei einer Beaufschlagung der Steckkupplung mit Druckkräften zu einer spielfreien Klemmung führt.

The trained as a receiving part 3 coupling element is generated by introducing a plurality of defined holes in the respective rod section 1. As a result, openings are formed whose walls cooperate with corresponding active surfaces of the corresponding male part 2 in order to transmit forces and moments. To form the receiving part 3, each rod section 1 has the following openings at one end:

• A central, in cross-section circular bore 9 is used in the engaged state of the plug-in coupling of receiving the locking shoulder 5 and each of a portion of the shaft 4 and the mandrel 7 of the male part 2 (see. Fig. 2 ). A portion of this central bore 9 is - like the locking portion 5 of the male part 2 - tapered conically. The conical surfaces of the Verriegefungsabsatzes 5 of the male part 2 and the central bore 9 of the receiving part 3 together form a (first) pair of coupling surfaces, which leads to a play-free clamping upon application of pressure to the plug-in coupling.

The central bore 9 merges on the front side into a mandrel opening 10 whose width is slightly greater than the distance between the two plane surfaces 8 of the mandrel 7; The mandrel 7 extends in the engaged state of the plug-in coupling with its front portion in this mandrel opening 10 (see. Fig. 2 ). The mandrel opening 10 runs on one side (in the Fig. 2 down), so that a corresponding opening is formed in the surface of the rod section (first side opening 11). The flat surfaces 8 of the mandrel 7 and the large side surfaces of the mandrel opening 10 thereby form a (second) Coupling surface pair out, which allows the transmission of torque in both directions.

The mandrel opening 10 merges into a section of a transverse bore 12.

In the rear end face 13 of the receiving part 3, a further, short (extending in the longitudinal direction of the rod assembly) bore 14 is introduced, whose diameter is smaller than that of the central bore 9 and also to one side (in the Fig. 1 to the top) runs out; There she goes into a (second) side opening 15, which extends into the conical section of the central bore. The laterally extending rear bore 14 and the (second) side opening 15 together form an L-shaped opening. The width of the L-shaped opening is only slightly above the distance between the two planar surfaces 6 of the locking shoulder 5 and is smaller than the (larger) diameter of the conical locking paragraph fifth

The (second) side opening 15 opposite a (third) side opening 16 is provided, which has a circular cross-section. The third side opening 16 merges into the (second) side opening 11 formed by the mandrel opening 10.

• Der das Steckteil 2 für die jeweilige Steckverbindung aufweisende Gestängeschuss 1 (in den Fig. 1 und 2 der linke Gestängeschuss) wird in einem Winkel von ca. 90° zu dem anderen Gestängeschuss 1 angesetzt und das Steckteil 2 durch die zweite Seitenöffnung 15 in das Aufnahmeteil 3 gesteckt. Dabei sind die Planflächen 6 des Verriegelungsabsatzes 5 parallel zu den Seitenflächen der L-förmigen Öffnung (und demnach auch parallel zu den Längesachsen der Gestängeschüsse 1) ausgerichtet. Der Dorn 7 erstreckt sich dabei in die dritte Seitenöffnung16.

A joining of the rod sections 1 by means of the plug-in coupling according to the invention takes place as follows:

• The plug-in part 2 for the respective connector having rod section 1 (in the Fig. 1 and 2 the left linkage) is attached at an angle of approximately 90 ° to the other rod section 1 and the plug-in part 2 is inserted through the second side opening 15 into the receiving part 3. In this case, the flat surfaces 6 of the locking paragraph 5 are aligned parallel to the side surfaces of the L-shaped opening (and therefore also parallel to the longitudinal axes of the rod sections 1). The mandrel 7 extends into the third side opening 16.

After insertion of the male part 2 having rod assembly 1 is rotated by 90 ° about its longitudinal axis. As a result, the edge forming the large diameter of the locking shoulder 5 is brought into contact with the inner surface of the central bore 9. At the same time, the (large) diameter of the locking section 5 protruding beyond the width of the L-shaped opening already prevents lateral and rear detachment of the plug-in coupling. The circular formation of the third side opening 16 thereby enables the rotation of the two-sided flattened mandrel 7.

The two rod sections 1 are then pivoted by about 90 ° into the coaxial position, as in the Fig. 2 is shown. In this position, the rear locking surface 17 of the locking shoulder 5 is located at the by the diameter jump formed between the rear bore 14 and the central bore 9 paragraph. The paragraph trained shoulder surface 18 and the rear locking surface 17 form a (third) coupling surface pair, can be transmitted via the tensile forces between the rod sections 1 (train position of the plug-in coupling). In this position, the plug-in coupling of the mandrel 7 already protrudes with its front portion already in the mandrel opening 10. This ensures that even in the train position of the plug-in torque in both directions can be transmitted. A pivoting of the mandrel 7 from the third side opening 16 into the mandrel opening 10 is made possible by the second side opening 11.

When exerting compressive forces, the two coupling elements are displaced relative to each other until it comes to the clamping of the first coupling surface pair (pressure position of the plug-in coupling - see. Fig. 2 ). In this position, the mandrel 7 projects a little way into the transverse opening 12; At the same time, it projects beyond a shoulder 19 formed between the transverse opening 12 and the second side opening 11. This prevents unintentional pivoting of the two rod sections 1 in the pressure position of the plug-in coupling. It is thus possible to transmit compressive forces without it being possible for an unintentional angling of the rod sections to one another and a consequent unwanted loosening of the plug-in coupling. A pivoting of the rod sections 1 is therefore possible only starting from the train position.

As a function of the amount of transmitted pressure forces an optionally strong clamping of the first coupling surface pair is generated, correspondingly high tensile forces may be required to switch the plug-in coupling from the printing position to the train position, as is necessary for a release of the plug-in coupling. Unless these tensile forces have been previously machined, e.g. by a retraction of the linkage under load, have been applied or can be applied manually, there is the possibility of a (widening) mandrel in the transverse opening 12 to strike, so that on the front end of the mandrel 7, extending in the printing position of the plug-in coupling extends into the transverse opening 12, releasing forces in the direction of the longitudinal axis of the rod section 1 are applied.

Claims (12)

1. Plug-in connector for a drill pipe with at least two connection elements, wherein the connection elements have at least one first corresponding connection surface pair designed in a tapering manner, so that a movement-free clamping is created when pressure forces are applied to the plug-in connection, characterised in that the connection elements have at least one second corresponding connection surface pair, via which a torque can be transmitted in a plugged-in condition and the first connection element has a mandrel (7) that is designed flattened on at least one side for forming a connection surface, and which engages a recess of the second connection element in the plugged-in condition, in which a corresponding connection surface is formed.
2. Plug-in connection according to claim 1, characterised in that the tapering angle is ≤ 10° and preferably ≤ 5° in relation to the longitudinal axes of the connection elements.
3. Plug-in connection according to claim 1 or 2, characterised in that the connection elements have at least one third corresponding connection surface pair, via which traction forces can be transmitted in a plugged-in condition.
4. Plug-in connection according to claim 3, characterised in that the first connection surface pair lies against each other in a first relative position of the connection elements to each other, and the third connection surface pair in a second relative position.
5. Plug-in connection according to claim 4, characterised in that the second connection surface pair lies against each other in both relative positions.
6. Plug-in connection according to one of the preceding claims, characterised in that the same is disconnectable in that the connection elements are first pivoted towards each other and at least one of the connection elements is then turned around its own longitudinal axis.
7. Plug-in connection according to one of the preceding claims, characterised by a transverse opening in one of the connection elements for receiving a wedge, wherein a force for disconnecting the clamping is applied to the other connection element by driving in the wedge.
8. Drill pipe with a multitude of pipe sections (1) which are connected with each other at least partially via a plug-in connection according to one of the preceding claims.
9. Drill pipe according to claim 8, characterised in that its front end is equipped with a diagonal control surface.
10. Drill pipe according to claim 8 or 9, characterised in that the foremost pipe section (1) is equipped with a locating sensor.
11. Drill pipe according to one of the claims 8 to 10, characterised in that the pipe sections (1) are of a tubular design, at least in some sections.
12. Drill pipe according to one of the claims 8 to 11, characterised in that the pipe sections (1) have a marking for determining the rolling.

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