EP4086426A1 - Rod lacing of a borehole rod - Google Patents

Abstract

The invention relates to a rod section of an earth drilling rod, the end of the rod section being designed to form a plug-in connection and having at least one end (a) a connector plug or (b) a connector socket, the connector plug on the outside or the connector socket on the inside having at least one circular section in cross section and has at least one more straight-like section.

Description

The invention relates to a rod section of an earth boring rod, an earth boring tool, the use of a rod section or an earth boring tool and a method for making an earth bore in the ground.

In rod-based drilling in the ground, in particular for the production of so-called horizontal bores, which can run essentially parallel or at a relatively small angle of inclination to the earth's surface, a drill head or drilling tool is advanced by means of a drill rod from a drive device arranged on the earth's surface or in an excavation. The drill rods used in this case usually consist of individual rod sections connected to one another which—according to the course of drilling—are gradually attached to the rear end of the drill rod that has already been drilled and connected to it.

Various configurations are known for connecting the rod sections to one another. The rod sections can thus be connected by means of a threaded connection and/or a plug-in connection.

Out of DE 10 2011 010 958 A1 it is known to provide a way of connecting two rod sections of a drill rod that combines the advantages of the threaded connections known from the prior art and the axial plug connections. In this case, a plug-in connection is described which - similar to a threaded connection - on a spiral on a circular in cross-section Threaded plug or projections/grooves running in a corresponding threaded bushing, the projections/grooves being designed in such a way that the self-locking characteristic of a threaded connection does not occur.

Proceeding from this state of the art, the invention was based on the object of specifying an improved plug-in connection for an earth drilling rod, in particular a rod section or earth drilling tool, and a use and a method. In particular, increased strength and/or reduced susceptibility to wear compared to other plug-in connections when drilling in the ground can be achieved.

This problem is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the respective dependent patent claims and/or result from the following description of the invention.

A (first) aspect of the invention, which in itself may constitute the basis of the invention or patent, relates to the configuration of the connector plug and/or connector socket of a plug-in connection of an earth drilling rod assembly. According to this aspect, the outside cross-section of the connector plug or the inside cross-section of the connector socket has at least one circular portion and at least one more straight-like portion. Surprisingly, such a shape is suitable for earth drilling with the resulting high loads and can have a corresponding strength or reduced wear, with the circular section or circular sections in particular not having to be involved in torque transmission. The torque can be transmitted via the more straight-like section or sections. Although not the entire length of the cross section or not the entire circumference is available for torque transmission due to the at least one more straight section, the plug connection can meet the high requirements for earth drilling in terms of load, wear and/or service life, which is surprising. With the surprising, suitable shape, a shape can be selected in which there can be a relatively small (conceptual) deviation from the shape of an overall circle. For example, there can be additional (building) space compared to a purely square design - e.g. in the corners, which cannot be present because a circular section is provided there - with the (building) space being available for another use, e.g. for laying or forming one or more channels for drilling fluid, a data line and/or a power line in the rod section. A simple creation of the cross section or circumference of the plug connection or the element of the plug connection can be made possible, since the cross section or circumference can only have a low level of complexity and by means of simple production machines, in particular NC machines, can be created or manufactured. A simple construction can be made possible for the user.

A rod section of an earth drilling rod is proposed, which is designed at the end to form a plug-in connection and has (a) a connector plug or (b) a connector socket at at least one end, the connector plug on the outside or the connection socket on the inside having at least one circular section and at least has a more straight section.

A further (second) aspect of the invention, which in itself may constitute the basis for the invention or patent, relates to the design of the connector plug and/or connector socket of a plug-in connection of an earth drilling rod assembly, the external cross-section of the connector plug or the internal cross-section of the connector socket having at least one section on which a contact surface for a securing element of the connector is configured. In this aspect, the invention has broken with the usual procedure of providing a safety element in a solid section or a core or arranging the safety pin in such a way that it essentially extends through a center point of the earth drilling rod in order to obtain the largest possible contact surface be able. It has been found that the arrangement of the security element or security elements described here is sufficient for many applications.

A rod section of an earth drilling rod is proposed, which is designed at the end to form a plug-in connection and has (a) a connector plug or (b) a connector socket at at least one end, and the connector plug on the outside or the connection socket on the inside has a cross section, the cross section being at least has a section on which a contact surface for a securing element of the plug-in connection is configured.

The two aforementioned aspects can be freely combined with one another, so that the cross section of the plug connection for the connector plug and/or connector socket can have the shape described and at least one contact surface for a securing element is provided on a section of the cross section.

The term "rod section" within the meaning of the invention comprises an element extending along a longitudinal axis, which element can be part of a ground drilling rod or a drill string for the soil. The rod section can be configured as a front-end element in the drill string with a dedicated function (a transmitter to Include locations and/or be designed as a front-side drilling tool or the like) or be designed as an element that merely lengthens the drill string as a “normal” rod section. The drill string may include mechanical conduits, such as for drilling fluid, electrical conduits, electrical elements, and/or electronic elements. Another (special) function of the linkage shot is not excluded.

A rod section can have a first end with a described configuration. The rod section (particularly when not configured as a front-end auger) may have a second end spaced from the first end which may be configured for connection to another rod section or an auger. The rod section may further include a centerline extending from the first end to the second end and extending along the rod section. The cross section under consideration of the connecting plug or the connecting socket can in particular be a cross section perpendicular to the center line of the rod section.

Within the meaning of the description, the rod section can in particular be a double-tube rod section in which both a so-called inner rod and a so-called outer rod are present. With such a double-pipe linkage, a drill head or earth-boring tool can also be driven in rotation via the inner linkage by the drive device arranged on the surface of the earth or in an excavation pit, which also provides for the propulsion of the drill head or earth-boring tool. For this purpose, the inner linkage can be mounted rotatably within the outer linkage of the double pipe linkage. The outer linkage in a double-pipe linkage is usually either not rotated at all or only at a low speed. The rotations of the outer rod and inner rod can be performed independently. A double pipe rod is particularly suitable for a rock drilling device, whereby the wear of the drill rod can be limited, because the outer rod in contact with the rocky hole wall can be advanced along the rocky hole wall without rotation or only at low speed, while the one with a higher Speed-driven inner linkage can be stored in the outer linkage to reduce wear. If the configuration relates to a double-pipe rod section, the inner rod and/or the outer rod of the double-pipe rod section can be configured at at least one end, as described in the description.

As used in the description, the term "earth drilling pipe" includes a drilling pipe that can be moved through the ground by means of an earth drilling device. Especially the Erdbohrgestänge can be pushed or pushed through the ground. The Erdbohrgestänge can be a rod section having rods that can be moved in an existing or to be created channel in the ground to create or widen a hole, especially a horizontal hole, or to introduce lines or other long bodies in the ground. In addition to the in particular pressing force, provision can also be made for the earth drilling device to drive the earth drilling rods in rotation. In particular, the earth-boring pipe can have an earth-boring tool at the front end which first comes into contact with the ground.

In the context of the description, the term "earth drilling device" includes any device that can in particular move a ground drilling rod in an existing channel or one that is to be created in the ground in order to create or widen a borehole, in particular a horizontal borehole, or to insert lines or other long bodies into digging in the soil. An earth drilling device can include a drive device that drives a drill string in a pulling and/or pushing manner. It can additionally or alternatively be provided that the drive device drives the drill string in rotation.

The term "horizontal drilling" (horizontal drilling) in the sense of the present description includes in particular any type of existing or to be created, preferably horizontal, channels in a body, in particular earth channels including earth drilling, rock drilling or earth lines as well as underground or above-ground pipelines and water channels that by using an appropriate earth drilling device or have it drawn in.

The term "plug-in connection" includes, in particular in the sense of the description, a connection of two elements of the earth drilling rod or two rod sections, in particular a rod section with an earth drilling tool, which is formed in a form-fitting manner in the direction of rotation about the center line or longitudinal axis, in which a at one end of one element of the earth drilling rod formed plug-in element of the plug-in connection can be positively plugged into one, formed on the other element of the Erdbohrgestänge other plug-in element of the plug-in connection. The plug-in elements can be brought into a positive connection with one another, by means of which a torque transmission between the two elements of the earth drilling rod is possible.

In a preferred embodiment, the plug-in connection is aligned coaxially with the rod section or the earth drilling tool, as a result of which a simple design can be achieved. The plug-in connection can be rotationally invariant, in particular if the connecting socket and the connecting plug essentially have rotational angle symmetry have, so that the connector socket and/or connector plug can be brought back into alignment by means of a rotation that is less than 360° around the longitudinal axis or central axis of the rod section or of the earth drilling tool. In particular, a rotational invariance of 180° or 90° can be provided. The construction of the connecting socket and/or connecting plug is not complex. The handling of the connector can be simplified on a construction site and thus difficult conditions.

A separation of the force-transmitting sections can be achieved on an element of the earth drilling rod assembly. Compressive forces can be transmitted, for example, via a stop on the plug connection between the connecting socket and the connecting plug. The stop for transmitting the compressive forces can be formed by means of an edge of the connecting socket and/or the connecting plug, which are at least partially in contact with one another when plugged together. A torque or rotational forces can be transmitted via the cross-sectional profile formed within the plug connection between a connector plug and a connector socket. Tensile forces can be transmitted via a securing element of the plug connection, for which purpose contact surfaces for the securing element can be formed on the respective element of the earth drilling rod.

The terms "connector plug" and "connector socket" as used in the description include an embodiment as one of a pair of mechanical coupling elements, one of which ("connector plug") can be at least partially inserted into the other ("connector socket") in order to to form a connection. The "connecting plug" does not necessarily have to comprise an element with a filled or solid cross-section, but it is also provided in particular that the inserted element can have a hollow core. The connector plug may have a free interior area; the connector plug can be designed in the form of a cylinder with a shell, and there can be free space inside the shell.

The term "cross-section" for the purposes of the description includes a sectional view transverse to the longitudinal direction of the connector plug or socket, which is transverse to the centerline of the rod section or earth boring tool. In particular, the cross section can be viewed at an angle of substantially 90° to the center line.

In this respect, the cross section on the outside of a connector plug can be a cross section that is at least partially configured for torque transmission to the connector socket. The outside cross-section can be combined with an inside cross-section be at least partially engaged, at least partially conforming to the outside cross-section.

The inside cross-section of a female connector may be a cross-section that is at least partially configured for torque transfer to the male connector. The inside cross-section may be at least partially engaged with an outside cross-section that at least partially conforms to the inside cross-section.

The term "circular portion" includes a portion that may substantially conform to the shape of a portion of a circle; In particular, the section can be designed in such a way that a torque in the case of a plug-in connection cannot or could be transmitted by means of the section designed on the cross section, or only to a very small extent, for example via static friction. The shape of a circular section itself can be designed in such a way that torque transmission cannot or could not take place.

The term "straight-like section" includes a section that essentially has a shape that differs from the "circular section", with the geometric design of the shape as a "straight-like section" being able to transmit torque in a plug-in connection by means of the section configured on the cross section . The "straight-like section" can essentially correspond to a straight line, with a slight curvature being able to be provided.

With regard to the distinction between “circular section” and “section more similar to a straight line”, a distinction can be such that the radius of curvature of the two sections that can be formed on a cross section or circumference differs. The "straight-like section(s)" can in particular have a curvature that corresponds to between 0% (not curved, straight line) and 50% of the curvature (curved only 1/2 times) of the circular section. It is possible to refer to the "more straight-line-like portion(s)" as the "torque-transmitting portion(s)" since torque is transmitted between the members of the connector substantially through the "more straight-line-like portion(s)". .

It may be possible that the cross-section may have a plurality of circular sections, which may have a substantially equal radius of curvature relative to substantially the same point. The more straight-like sections can be configured as substantially straight sections with low curvature, ie higher radius of curvature with different centers of curvature be formed, wherein all straight more similar sections can preferably have the same radius of curvature. Provision can be made for the more straight-like sections to be in the form of straight lines, in particular essentially as secants on a circle that forms sections for the circular sections. The cross-section can be initially constructed - in a first step - as a circle in the construction, with sections of the circle forming the circular sections and the more straight-line-like sections inserted between the sections of the circle (circular sections can be replaced by more straight-line-like sections) and so on Form the cross section together for the plug connection. In a particularly preferred embodiment, the cross-section is point-symmetrical to the center through which the longitudinal axis of the plug-in connection or the longitudinal axis of the rod section runs, consisting of circular and straight-like sections. As an alternative or in addition, the cross section can have an axisymmetric design, with the axis of symmetry running transversely to the longitudinal axis, intersecting the center point. There can be several axes of symmetry. Provision can be made for the number of circular sections and straight-like sections to be the same and in particular to be four.

In a preferred embodiment, the circular portion and the more straight-like portion are connected to each other in a continuous or smooth manner, wherein for the purposes of the description the term "continuous" or "smooth" describes a property of the cross-section according to which the cross-section has essentially no discontinuities, i.e., the change in the function values describing the cross-section can be limited at will by restricting oneself to sufficiently small changes in the argument, for example in the polar angle. The term "continuous" or "smooth" refers to a macroscopic consideration, in which minor, in particular microscopic, discontinuities may be present, but in particular a radially running macroscopic section or several radially running macroscopic sections can be excluded or not be present . "Continuous" or "smooth" can describe or refer to a cross section that has no edges or is designed without edges.

In a preferred embodiment, the more straight-like section has a radius of curvature that is more than 1.5 times, in particular more than 2 times, larger than the radius of the circular section. As a result, a separation of torque-transmitting and non-torque-transmitting sections can be achieved, which can be easily constructed and manufactured with simple means.

In a preferred embodiment, the more straight-line portion intersects a circular portion having a radius less than the radius of the circular section. A simple construction of the connector or the elements of the connector is possible.

In a particularly preferred embodiment, the cross section is at least partially P4C-shaped.
The concept of a configuration of a cross section as “P4C-shaped” in the sense of the description includes the so-known polygonal profile P4C, with deviations from the pure shape being possible, which are caused in particular by tolerances during manufacture. Insofar as it is described that the cross section “at least partially” essentially has the described shape, this includes that in particular (peripheral) sections of the cross section can be present that are not P4C-shaped. It can be important that the P4C-shaped sections of the cross section can be present, but other sections can also be present. In particular, a P4C-shaped cross section can be characterized in that it can be configured P4C-shaped at portions of the cross section that transmit torque. A P4C-shaped cross-section can also have a torque-non-transmitting section or several of these sections, which or which can be designed differently than the P4C-shape dictates without impairing the function of the torque transmission.

By means of the described configuration of the cross-sectional shape, a plug-in connection can be created through which a very high torque can be transmitted, whereby it can be achieved that the two elements of the earth drilling rod to be connected touch each other over a large area in relation to the cross-section, so that there is a significant reduced surface pressure can occur. A notch effect can be avoided.

The configuration of the cross-section as at least partially P4C-shaped in the circumferential direction on the connection socket and/or connection plug is not necessarily present over the entire length of the connection socket and/or the connection plug, but can extend over the entire length.

The term "contact surface" in the sense of the description comprises a surface for which an element, in particular the securing element, which is at least partially adapted to the shape of the contact surface, can be present. A connection can be realized by the contact of the element or securing element on the contact surface. The contact surface can have a surface area that runs transversely to the longitudinal direction of the rod section or earth boring tool.

The term "fuse element" in the sense of the description includes a component that causes two elements to be secured to one another, in which the fuse element in particular on a contact surface of one of the two elements, in particular on a contact surface of each of the two elements. The securing element can be inserted into the plug-in connection formed to rest on the contact surface(s). The securing element can extend through or be inserted into a bore running through the connecting socket and connecting plug. The securing element can be an elongated or rod-shaped element which can be introduced into the connector plug and connector socket. The securing element can at least partially form a non-positive, positive and/or material connection with the contact surfaces, so that the plug connection can be fixed in the longitudinal direction of the plug connection by means of the securing element. The securing element can be screwed, inserted, pushed, pressed and/or glued into or onto the contact surface(s). The securing element can be designed as a dowel pin, the diameter of which is chosen so that it can be compressed by a desired amount when installed. The dowel pin can be inserted into a hole in the connector plug and connector socket that are aligned with one another. The contact surface(s) described can be produced by means of a bore. A roll pin can be easily assembled and disassembled. In addition, a bearing surface or bearing surfaces for the dowel pin can be well designed and manufactured. A dowel pin enables assembly/disassembly without special tools.

The term "bore" in the sense of the description includes a recess or an opening, which can be configured round in cross section. The term bore also includes a depression and/or a breakthrough that is not completely surrounded by material. In particular, no material can be present in a direction that does not impair the safety function. The term bore also includes a recess in a direction transverse to the longitudinal direction of the connector socket or the connector plug, so that the bore or recess has a contact surface which interacts with the securing element in the event of a tensile load. The bore or recess can bear against the securing element with its contact surface. The term bore is not limited to a recess, an indentation or a recess that is produced by means of a rotating tool with the corresponding mechanical removal of chips or fragments, but also includes production by means of spark erosion, oscillating lapping and/or a laser.

In a preferred embodiment, in the case of the linkage section, the plug-in connection can be realized by means of a connecting socket, which has a through hole for inserting the securing element. In this way, easy access can be made possible in that the securing element can extend through the connection socket. For example, the fuse element on one side of the Through hole introduced and ejected to the other side. In a preferred embodiment, the through-hole is arranged in such a way that the longitudinal axis of the through-hole describes an angle with a line passing through the center line of a cross section. The through-hole can extend in such a way that the longitudinal axis of the through-hole does not intersect the center line of the rod section or the earth boring tool. The through-holes can be formed circumferentially on the inside cross-section. A plurality of through bores are preferably formed circumferentially on the inside cross section, which can essentially have an equidistant distance from one another. The (through) hole can be a secant of the cross section. In a particularly preferred embodiment, there is more than one through hole. For example, there can be a through hole for each securing element. In particular, the through hole can be formed in an area of the cross-sectional profile that is not used for the torque-transmitting function of the inside cross-section of the plug-in connection. For example, two through-holes for two safety elements, three through-holes for three safety elements and in particular four through-holes for four safety elements can be provided. The securing elements may be spaced around the circumference of the inside cross-section of the connector socket; the through holes or the securing elements are circumferentially distributed around the cross section. In a particularly preferred embodiment, there are four through-holes, in particular with a P4C-shaped cross section, which can be provided in particular in areas that are not intended for the torque-transmitting function.

In a preferred embodiment, the rod section has a transmitter which, in particular, enables the earth drilling rod to be located. A string section having a transmitter is usually arranged in the front area of the earth drilling string. In most cases, the rod section having a transmitter is used as the rod section which is arranged behind the auger tool.

In a preferred embodiment, the rod section or the earth boring tool has another connection at the other end spaced from the end for connection to a further rod section. This allows you to switch to a different type of connection on the other side of the rod section.

In a preferred embodiment, the rod section is designed as a double-tube rod section. In a particularly preferred embodiment, the plug connection is present on the outer rod section of the double-pipe rod section. As a result, variability and flexibility can be achieved. The inside linkage shot can be connected to the plug connection differently than in the present case. It can be based on different possible uses or requirements.

The configuration described with regard to the cross-sectional shape is not limited to a section of an earth drilling rod that is usually referred to as a rod section, but can also relate to the configuration of an earth drilling tool, so that, according to an aspect that is the basis of the invention in and of itself, an earth drilling tool can relate that has a connecting plug and/or may have a connecting socket for forming a plug connection of an earth drilling rod. According to this aspect, the outside cross-section of the male connector or the inside cross-section of the female connector of the earth boring tool is at least partially formed into a P4C shape.

The term "earth boring tool" includes a boring head arranged at the front end of the boring rod or drill string, which can have moving parts. However, it can also be provided that the earth boring tool has an immovable or rigid or largely immovable or rigid outer contour.

An earth drilling tool is described which is designed at the end to form a plug connection and has (a) a connector plug or (b) a connector socket, the connector plug on the outside or the connection socket on the inside having at least one circular section and at least one more straight section.

The design described with regard to the contact surface on at least one section of a cross section is not limited to a rod section per se, but can also relate to the design of an earth drilling tool, so that according to an aspect that is the basis of the invention, an earth drilling tool has a connector plug and/or a connector socket for forming a plug-in connection of an earth drilling rod assembly, a contact surface for a securing element of the plug-in connection being configured on at least one section on the outside cross-section of the connecting plug or on the inside cross-section of the connecting socket.

An earth drilling tool is described, which is designed at the end to form a plug connection and has (a) a connector plug or (b) a connector socket, and the connector plug has a cross section on the outside or the connection socket on the inside, the cross section being at least has a section on which a contact surface for a securing element of the plug-in connection is configured.

In a preferred embodiment, the earth boring tool is suitable for making a pilot bore, in particular a rock bore. This means that ground boring tools can be used, which are usually only pushed or pushed through the ground. When drilling a rock or drilling a pilot hole, slight tensile forces can act, which can then be transmitted by means of the securing element or the securing elements and the corresponding contact surfaces.

The invention also relates to a drill rod section of an earth drill rod, in which a rod section configured in accordance with the description is connected to an earth boring tool configured in accordance with the description.

The invention also proposes using a rod section or an earth boring tool in which the rod section or the earth boring tool is designed at the end to form a plug connection and has (a) a connector plug or (b) a connector socket on at least one end, with the connector plug being on the outside or the female connector has at least one circular portion and at least one more straight portion on the inside.

The invention also proposes using a rod section or an earth boring tool in which the rod section or the earth boring tool is designed at the end to form a plug connection and has (a) a connector plug or (b) a connector socket on at least one end, and the connector plug on the outside or the connecting socket has a cross section on the inside, a cross section being used which has at least one section on which a contact surface for a securing element of the plug connection is configured.

The two aforementioned uses can be freely combined with one another, so that the cross section of the plug connection for the connector plug and/or connector socket can have the shape described and at least one contact surface for a securing element is provided on a section of the cross section.

The invention also proposes a method for making an earth hole in the ground, a rod section or an earth drilling tool being provided, the rod section or the earth drilling tool being designed at the end to form a plug-in connection and at one end (a) a connecting plug or (b) has a connector socket, and the cross section of the connector plug outside or the connector socket inside has at least one circular portion and at least one more straight-like portion.

The invention also proposes a method for drilling an earth hole in the ground, wherein a rod section or an earth drilling tool is provided, the rod section or the earth drilling tool being designed at the end to form a plug connection and at least one end having (a) a connector plug or (b) a Having connecting socket, and the connecting plug on the outside or the connecting socket on the inside has a cross section, a cross section being provided which has at least one section on which a contact surface for a securing element of the plug connection is configured.

The two aforementioned methods can be freely combined with one another, so that the cross section of the plug connection for the connector plug and/or connector socket can have the shape described and at least one contact surface for a securing element is provided on a section of the cross section.

If a device, in particular in the form of a rod section or an earth boring tool, a method and a use are described in the description, the explanations of the individual aspects complement each other. In particular, the explanations of the performance, in particular with regard to the features of the same, also apply to the method and to the use.

Numerical information within the meaning of the description is information that may have a tolerance of +/- 10%, so that the numerical information not only describes one value, but a range of values, in order to take account of tolerance ranges that may be production-related.

The above statements, like the following description of an exemplary embodiment, do not represent a waiver of certain embodiments or features.

The invention is explained in more detail below with reference to an exemplary embodiment illustrated in the drawings.

Fig. 1

eine isometrische Ansicht eines Verbindungssteckers;

Fig. 2

eine Ansicht einer Verbindungsbuchse in Richtung der Mittellinie der Verbindungsbuchse;

Fig. 3

eine isometrische Ansicht der Verbindungsbuchse von Fig 2;

Fig. 4

eine Seitenansicht einer ineinandergesteckten Steckverbindung von Verbindungsstecker gemäß Fig.1 und Verbindungsbuchse von Fig. 2 und 3;

Fig. 5

einen vorderseitigen Abschnitt eines Doppelrohr-Erdbohrgestänges in teilweise geschnittener Darstellung; und

Fig. 6

eine Detailansicht der Fig. 5.

In the drawings shows:

1

an isometric view of a connector plug;

2

a view of a connector socket in the direction of the center line of the connector socket;

3

an isometric view of the connection socket of figure 2 ;

4

a side view of a mated connector of connector according to Fig.1 and connector from 2 and 3 ;

figure 5

a front section of a double tube earth drilling pipe in partial section; and

6

a detailed view of figure 5 .

1 shows a schematic isometric view of a connecting plug 1, as can be formed at the end of a rod section or an earth boring tool. The end of the rod section or earth boring tool is designed to form a plug connection. The connector plug 1 is part of a pair in the illustrated embodiment, which also has a connector socket 2, as is particularly the case in connection with figure 2 and 3 is described, has.

the 1 1 shows an outside cross-section 3 on the connector plug over a length Q, which cross-section is adapted to an inside cross-section 4 connecting socket 2 .

The outside cross-section 3 of the connector plug 1 and the inside cross-section 4 of the connector socket 2 have four circular sections 17, 17a and four more straight-like sections 18, 18a. The four circular portions 17, 17a and the four more straight-like portions 18, 18a of a circumference and cross-section, respectively, result in a P4C-shaped configuration. Over the length Q, connector plug 1 and connector socket 2 cooperate by means of the P4C-shaped cross-section to transmit a torque from connector plug 1 to connector socket 2 and vice versa.

A pushing force can be transmitted between the connecting socket 2 and the connecting plug 1 by means of abutment surfaces 5, 6, which lie against one another when plugged together.

In order to form a fuse for the plug-in connection, holes are made in the connector plug 1 and the connector socket 2, into which a fuse element can be inserted.

The bores are formed in the connecting sleeve 2 by means of through bores 7, 8, 9, 10. In the outer edge area, the through bores come out at the holes 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b. In the connection socket 2, open recesses are formed by the bores in the inside cross section 4, of which a recess 9c in 3 is shown.

On the connector 1, the holes lead to recesses 11, 12 with a corresponding contact surface for the fuse element.

The bores or recesses 7, 8, 9, 10, 11, 12 are formed in the cross-sectional section or area in which the P4C-shaped cross section does not have the function of transmitting torque.

Figures 5 and 6 show a double-pipe rod section 16, with inner rod section 13 and outer rod section 14. The outer rod section 14 of the double-pipe rod section 16 is connected to an earth boring tool 15 by means of a plug-in connection described above.

Claims (16)

Rod section or earth drilling tool (15) of an earth drilling rod, the rod section or earth drilling tool (15) being designed at the end to form a plug-in connection and having (a) a connecting plug (1) or (b) a connecting socket (2) at at least one end, characterized in that characterized in that the connector plug (1) on the outside or the connector socket (2) on the inside has at least one circular section (17, 17a) and at least one more straight section (18, 18a) in cross section (3, 4). Rod section according to claim 1, wherein the circular portion (17, 17a) and the more straight-like portion (18, 18a) are continuously or smoothly connected to each other. Rod section according to claim 1 or 2, wherein the more straight-like section (18, 18a) has a radius of curvature which is more than 1.5 times, in particular more than 2 times, larger than the radius of the circular section (17, 17a). A rod section according to any one of claims 1 to 3, wherein the more straight-line portion (18, 18a) intersects a circular portion having a radius smaller than the radius of the circular portion (17, 17a). Rod section according to one of claims 1 to 4, wherein the cross section is at least partially P4C-shaped. Rod section or earth drilling tool (15) of an earth drilling rod, in particular according to one of claims 1 to 5, wherein the rod section or the earth drilling tool (15) is designed at the end to form a plug connection and at least one end has (a) a connecting plug (1) or (b ) has a connecting socket (2), and the connecting plug (1) on the outside or the connecting socket (2) on the inside has a cross section (3, 4), characterized in that the cross section (3, 4) has at least one section (17, 17a) has, on which a contact surface (11, 12) is designed for a securing element of the plug connection. Rod section according to Claim 6, characterized in that the connecting bush (2) has a through bore (7, 8, 9, 10) for inserting the securing element. Rod section according to one of Claims 1 to 7, characterized in that the rod section has a transmitter. Rod section according to one of Claims 1 to 8, characterized in that the rod section has another connection at the other end spaced from the end for connection to a further rod section. Rod section according to one of Claims 1 to 9, characterized in that the rod section is a double-tube rod section (16). Rod section according to Claim 10, characterized in that the plug-in connection is present on the outer rod section (14) of the double-pipe rod section (16). A drill string portion of an earth drilling string wherein a drill string as claimed in any one of claims 1 to 11 and an earth drilling tool (15) as claimed in any one of claims 1 to 11 are connected. Use of a rod section or an earth drilling tool (15), the rod section or the earth drilling tool (15) being designed at the end to form a plug-in connection and having (a) a connecting plug (1) or (b) a connecting socket (2) at at least one end, characterized in that the connector plug (1) on the outside or the connector socket (2) on the inside has at least one circular section (17, 17a) and at least one more straight section (18, 18a). Use of a rod section or an earth boring tool (15), in particular according to claim 13, wherein the rod section or the earth boring tool (15) is designed at the end to form a plug connection and at least one end has (a) a connector plug (1) or (b) a connector socket (2) and the connector plug (1) on the outside or the connector socket (2) on the inside has a cross section (3, 4), characterized in that a cross section is used which has at least one section (17, 17a) on which a contact surface (11, 12) is designed for a securing element of the plug connection. A method for making an earth bore in the ground, wherein a rod section or an earth boring tool (15) is provided, the rod section or the earth boring tool (15) being at the end to form a plug-in connection and has at one end (a) a connecting plug (1) or (b) a connecting socket (2), and the cross section of the connecting plug (1) on the outside or of the connecting socket (2) on the inside has at least one circular section (17, 17a) and at least one more straight-like section (18, 18a). Method for making an earth bore in the ground, in particular according to claim 15, wherein a rod section or an earth drilling tool (15) is provided, the rod section or the earth drilling tool (15) being designed at the end to form a plug connection and at least one end (a) having a Connecting plug (1) or (b) has a connecting socket (2), and the connecting plug (1) on the outside or the connecting socket (2) on the inside has a cross section (3, 4), a cross section being provided which includes at least one section (17 , 17a), on which a contact surface (11, 12) is designed for a securing element of the plug connection.

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