EP3231980B1 - Drilling head with a chisel holder and a method of assembling the same - Google Patents

Description

The present invention relates to a drill head with a drill head body in which a plurality of drill pins and / or drill rails is fixed in corresponding receiving openings, a drill head shaft, which is designed for connection to a selected from a further shaft part or an adapter element, at least one Recess for the removal of cuttings and optionally at least one opening for dispensing flushing fluid and a method for assembling a drill head consisting of a drill head body, in which a plurality of drill pins and / or drill rails is defined in corresponding receiving openings, a drill head shaft, which for connection to a from a further shaft part or an adapter selected element is adapted, which has at least one recess for the removal of cuttings and optionally at least one opening for dispensing flushing fluid.

In conventional devices for drilling holes in soil or rock material usually a drilling device with a drill head, on which a plurality of drill bits or drill pins or drill rails are attached, connected either by means of an adapter or directly to a drill pipe, which the drill head by means of a striking or rotating movement in the soil or rock material brings. In order to be able to safely remove drill cuttings occurring during this introduction or the release work, the drill head is usually surrounded by an envelope or jacket tube, and this jacket or jacket tube is either hammered or drawn into the borehole. In the variant in which the casing or casing tube is drawn into the borehole, as in the prior art, the drill head or the adapter connected to the drill head via impact surfaces, impact shoulders or other driver with the casing or casing tube engaged to bring this into the interior of the borehole.

That is how it is WO 2005/033467 A1 discloses a method and apparatus for drilling holes in soil or rock material, wherein a drill bit supported on a drill string is used to create a wellbore, and a cladding tube is inserted into the wellbore to be drilled simultaneously with the drill bit. Here, the impact energy introduced by a drill string is partially applied by the drill string on the drill bit and partially on a transferred to the jacking or cladding tube cooperating with the drill string.

According to the EP 1 818 499 B1 US 5,500,855, which describes a device for simultaneously drilling and lining wells, a drill bit mounted on an adapter is used to form a wellbore by means of a drill string, which adapter acts both on the drill bit and the adapter is in striking contact with a cladding tube, so too the cladding tube is inserted through the adapter into the borehole.

In such known solutions, both the adapter of the drill head or the drill bit is separable, as well as the drill pipe from the adapter separable and finally a detachable from the adapter impact ring is provided which interacts with a corresponding impact shoe or impact element of a cladding tube, to bring the cladding tube into the interior of a borehole. Due to the large forces that must be expended for forming the borehole, there is thus the danger that such releasably connected elements inadvertently separate from each other during operation, for example, the adapter is separated from the drill bit, whereupon a further drilling or further propulsion of the drill head in the interior of the borehole is no longer possible, since the required for a successful drilling centering drill bit, adapter and drill pipe can not be guaranteed more. In such a case, the wellbore must be abandoned and at least the drill string and, if possible, portions of the cladding tube retrieved from the well to minimize the damage. In order to successfully continue drilling, it is necessary in such a case to assemble a new unit of drill head, adapter, drill pipe and cladding to start a new well, resulting in not only material damage but also weakening of the rock due to the abandoned wells Finally, a not inconsiderable amount of time is required for the preparation of the required holes, since each abandoned hole is of course in addition to the material damage to the equipment used also associated with a considerable amount of time.

The invention now aims to provide a drill head with a drill head body, with which it succeeds in a drilling and / or rotary impact drilling simultaneously with the formation of the borehole a cladding tube in the interior of the borehole in which a risk of unintentional disconnection of the drill head from the shaft or the adapter used for insertion is kept behind.

Furthermore, the present invention aims to provide a method for assembling a drill head with a drill head body, with which it is possible to provide a drill head and drill head body, which ensures a safe and reliable introduction of a cladding tube into a borehole simultaneously with the Formation of the borehole ensured.

To solve this problem, the device according to the invention is essentially characterized in that the drill head shaft is formed as provided with a first connecting element for connection to the further shaft part stub shaft, that directed to the drill head end portion of the substantially tubular further shaft portion or the adapter with a cooperating with the first connecting element of the Bohrkopfschafts second connecting element is formed, that an end face of the further shaft portion or the adapter facing the well head is formed with at least one substantially annular abutment part and that one to the substantially annular abutment part engageable, the other Shank part or the adapter surrounding driver is provided. By forming the Bohrkopfschafts in two-part form with two connecting elements, which are inextricably linked to each other in the assembled state of the drill head with the Bohrkopfkörper and arranging a driver to the two connected shaft parts succeeds in forming a drill head, which a driver for a einzubringendes Cladding tube has inseparably arranged by the drill head on the shaft thereof. Furthermore, by at least the shank part facing away from the drill head having a substantially annular abutment part, with such a design it is not only possible to introduce a cladding tube into it simultaneously with the formation of a borehole, but in particular sufficient impact or rotational impact energy on both Bohrkopfkörper as well as to apply the driver, so that in this way the drill head together with the driver and it can be fixed securely inserted into the inside of a hole to be formed. Further, by the drill head shaft is formed so that a shaft portion is formed with a first connecting element as a stub shaft, it is ensured that the shaft length can be kept relatively short overall, which not only saves material, but in particular any risk of deviating Drill head from the desired direction by curving, buckling or the like. Stub shaft is held back, so that clean and straight holes can be formed. Furthermore, the shaft parts to be joined could also be formed from mutually different materials, so that, for example, expensive materials for drill head body including stub shaft are used and the remaining components are made of less expensive materials, whereby not significant cost advantages, especially in lost drill bits are achieved.

The driver according to the invention is also referred to as a "striking star". This designation is primarily intended to characterize the shape of the driver, which is essentially star-shaped. The star-shaped configuration may in this case be chosen such that between four and six extensions or corresponding recesses are provided.

The drill head body is also referred to by experts as a crown body and also the drill head as such may be referred to as a drill bit. Regardless of the choice of designation, a drill head body or drill bit body is understood to mean that part of the drill head or drill bit in which the release tools are inserted.

By the connecting elements are selected for connecting the stub shaft with another shaft part of cooperating threaded parts, connector parts such as bayonet connection elements or clamp connection elements, it is possible to provide a releasable connection in a first step, which, if necessary, be solved again at any time can, for example, be such a release then be necessary if it turns out that the driver is incorrectly dimensioned, the wrong drill bit was selected and another drill bit with other drilling pins or drill bars must be used or even the second shaft part not according to Borehole environment was selected. With such a design, it is thus possible, before the final connection, in particular before the permanent connection of two shank parts with each other, easily and reliably replace individual components in order to adapt the drill head to the desired conditions. Furthermore, a releasable connection is provided, which, however, is sufficiently stable that it must not be feared even in rough drilling operation that an unintentional loosening or rising the same happens, even if, for example, in the production of short holes on a soldering of the connecting parts is omitted.

In order to provide a further security for an unintentional release of the two connecting elements from one another, according to a development of the invention, the procedure is such that, in addition, an indissoluble fixing of the first and second connecting elements to one another with a solder is provided. In addition, by a non-releasable fixing of the first and second connecting elements to each other by means of solder, it is ensured that unintentional loosening of the two connecting elements and thus the drill head with the stub shank of the other shaft part, even when drilling in hard rock with certainty is stopped. On the other hand, however, after the provision of the solder joint further exchange or further adaptation and adaptation of the drill head to expected conditions is no longer possible. It is therefore useful in operation to proceed so that on the one hand the elements to be joined are selected according to the requirements and releasably connected in a first step by, for example, a screw, bayonet or the like. Provided and achieved in a second step in the first step detachable connection is made by introducing solder into a permanent connection, if tests have shown that the choice of the individual parts corresponds to the existing conditions.

Drilling heads with their shank parts are relatively expensive due to the fact that they are usually made of hard metal or high-quality steel. Usually, however, in order to meet the requirements for mining rock material from the interior of a wellbore, it is sufficient to manufacture only the area of its head or area in which drilling pins or drill rails are inserted from suitably highly tempered materials. For facing away from a drill hole parts of the drill head therefore usually provides the provision of normal steel grades. In order to be able to take better account of such requirements, according to a further development, the drill head is designed so that the stub shank is formed integrally with the drill head body and that the stub shank is formed from a different material from the further shank part or adapter to be connected therewith.

In order to be able to entrain in particular a tube to be introduced into the borehole without twisting or twisting thereof, according to an embodiment of the invention, the boring head is designed such that the driver is movably, in particular rotatably arranged on the further shaft part or the adapter. The movable or rotatable arrangement of the driver ensures that the cladding tube, which is drawn by the rotatably mounted driver into a borehole, is introduced straight into the borehole without any twist, while the boring head carries out, for example, a rotary boring performs. By the rotatable arrangement of the driver remains when the drill head is rotated, the driver at rest and thus it can be a cladding tube and it can thus be retracted without any twisting and twisting.

In order to ensure a safe removal of cuttings into the interior of the cladding tube and to ensure a removal of the same from the borehole out, according to an embodiment of the invention, the drill head is formed so that the driver has at its outer periphery a plurality of recesses. By the plurality of recesses on the outer periphery of the driver cuttings can be introduced into the interior of the cladding tube and transported safely and reliably to the exterior of the wellbore.

By, as corresponds to a development of the invention, the drill head is designed so that a directed to the drill head body outer peripheral portion of the driver contoured, in particular curved, it is possible to take the jacket tube safely without slipping or accidental slipping of the driver is to be feared by the cladding. With such a contouring, in particular curved contouring, the driver has a region of smaller diameter and a region of larger diameter, and the region of larger diameter engages with a region of smaller diameter of the cladding, so that this is safely and reliably entrained: Here is the Drilling head formed so that the contouring of the outer periphery of the driver is designed as an engaging and / or holding element for a possibly cooperating with the drill head beginner tube or cladding tube. With such an engaging and / or holding element, a safe entrainment of the beginner tube or cladding tube into the interior of the borehole, in particular by inserting the driver into the cladding tube, can be achieved without fear of tearing or slipping of the driver through the cladding tube.

By, as this corresponds to a development of the invention, the further shaft portion or the adapter is provided at its side facing away from the drill head body end portion with an internal thread, this can be connected to either another adapter or a drill rod by simply screwing, making a particularly simple and Reliable assembly of a complete system succeeds.

By, as this corresponds to a development of the drill head according to the invention, the further shaft part or adapter is formed with two substantially parallel stop members, a particularly uniform introduction of the drill head is ensured in the interior of the borehole.

By, as this corresponds to a development of the drill head, the stop members are designed as substantially normal to a rotation axis through the drill head body, the further shaft part or the adapter directed substantially annular abutment surfaces, the largest possible stop surfaces are provided and in particular a uniform application of the entire Adapters ensured, whereby the service life of the entire system is extended.

In connection with the present invention further appears to be essential to collect a cladding tube simultaneously with the introduction of the drill head into the interior of the drill head, while ensuring that not by an unintentional separation of the drill head and drill string or adapter, for example, the drill head in the interior of the wellbore is introduced, but the cladding tube is not entrained or that the cladding tube breaks out during the introduction or eventually there is an uneven movement of the entire drill head into the interior of the drilled hole. The invention therefore further relates to a method of assembling a boring head according to the invention in order to provide a boring head which, on the one hand, safely and reliably withstands the movements during boring and, on the other hand, at the same time continuously a duct into the interior of a borehole can move in.

To solve this problem, the inventive method is essentially characterized in that arranged on a substantially tubular-shaped further shaft part or adapter, the further shaft part or the adapter surrounding driver, in particular rotatably arranged that the other Shaft part or the adapter by means provided thereon first and second fasteners in or on one provided on the formed as a stub shaft drill head shank fastener is releasably determined that after detachably fixing the other shaft part or the adapter to the stub shank of Bohrkopfkörpers, by welding, soldering or Riveting the other shaft part or the adapter with the stub shank of Bohrkopfkörpers a permanent connection is formed and that the insoluble compound is optionally subjected to a temperature treatment. With such a method for assembling a drill head, it is possible to form a unit which on the one hand comprises the drill head, on the other hand has a driver for the jacket tube and finally has this driver mounted on the drill head shaft such that unintentional twisting or twisting of the jacket tube during the Entry into the borehole is avoided. Since this method essentially forms an element which has all the properties which a drill head and a beginner tube as well as an adapter have, a clear apparatus simplification is achieved with an extremely simple method of assembling.

Furthermore, by carrying out the method such that the transfer to a non-detachable connection is formed by soldering, in particular vacuum soldering, it is ensured that unintentional detachment of the individual parts forming the drill head and the driver from one another, regardless of the direction of rotation of the drill head, is at any rate refrained from. Such a device is used to guide the process so that simultaneously with the introduction of the drill head and the cladding tube is introduced into the interior of the well, after completion of the drilling process, the drill string is separated from the drill head and these parts as a lost drill head in Inside the hole remain.

In order to provide a particularly stable connection, which is unstable in particular in the harsh environment of mining, the method according to the invention is further developed such that, after brazing, a heat treatment, in particular annealing, is carried out. By performing a heat treatment, in particular tempering, after soldering, it is ensured that the solder joints are not subject to any stresses and can withstand the massive stresses of forming a hole in soil and rock material with certainty. Furthermore, it is possible with such a process management form a drill bit, in which the individual components made of different steel grades are, as built by a temperature treatment internal stresses and cracking or breaking of the connection is prevented. Finally, it is achieved with such a process control that the existing residual heat can be used during annealing or after annealing to form structural changes in the steel grades. By such a structural change, the breaking strength of the material is increased by up to 20%, thereby further increasing the stability of the drill head. Moreover, with such a process control, the use of different steel grades can be made specifically. Thus, expensive materials can be used for only the drill head body and for the shaft parts or in particular the further shaft part cheaper materials or softer steel grades can be used without the risk of premature wear or breakage of the drill head is to be feared.

By, as corresponds to a development, the process is performed so that the temperature and / or duration of the annealing are chosen such that in the other shaft part or the adapter during annealing, a structural change is effected and that the driver and Bohrkopfkörper of a If different materials are formed by the further shaft part or the adapter, in particular a saving in the materials used for the drilling head can be achieved. By annealing the formation of a structural change is achieved, so that even clearly different materials, in particular materials with different expansion coefficients can be safely and reliably connected.

• Fig. 1 einen Schnitt durch den Bohrkopf sowie ein an diesen angelenktes Hüllrohr,
• Fig. 2 den Bohrkopf von Fig. 1 in der Ansicht von außen,
• Fig. 3 den Bohrkopf von Fig. 1, bei welchem das Hüllrohr weggelassen ist,
• Fig. 4 eine andere Ausbildung eines Mitnehmers sowie des weiteren Schaftteils in der Ansicht von außen, und
• Fig.5 eine Draufsicht in der Perspektive auf einen Mitnehmer gemäß der Erfindung.

The invention will be explained in more detail with reference to embodiments shown in the drawing. In these show:

• Fig. 1 a section through the drill head and a hinged to this cladding tube,
• Fig. 2 the drill head of Fig. 1 in the view from the outside,
• Fig. 3 the drill head of Fig. 1 in which the cladding tube is omitted,
• Fig. 4 another embodiment of a driver and the other shaft part in the view from the outside, and
• Figure 5 a plan view in perspective of a driver according to the invention.

In detail is in Fig. 1 1 designates a drill head which is articulated from a drill head body 2, on which a part of a drill head shaft 3 designed as a stump shank is articulated, and also a further shank part 4, which can also serve as an adapter, consists, wherein the shaft part 4 with the drill head shaft 3 in the in Fig. 1 shown training is shown in the connected state. Surrounding the shank parts or the drill head shank 3, 4 is provided a driver or striking star 5, which driver 5 is formed during the formation of a borehole for drawing in a sheath tube 6 into the borehole. In the drill head body 2 in this case a plurality of drill pins 7 are provided in corresponding receiving openings, which drill pins 7 may be formed differently in both the shape and in number and their arrangement in the drill head body 2. Furthermore, the drill head body 2 has an opening 8 for discharging flushing fluid, which opening 8 communicates with a corresponding recess or conduit 9 in the interior of both the drill head shaft 3 and the further shaft part or adapter 4 in order to reliably supply the flushing fluid the opening 8 in the drill head body 2 to be able to perform. For the illustrated embodiment, the opening 8 is formed as a backwash. Finally, the lower free end of the further shaft portion or adapter 4 is designed to be connected to, for example, a boring bar, which in Fig. 1 not shown to connect. The further shaft part 4 as well as the drill head shaft 3 are in the in Fig. 1 shown training screwed together, wherein in the region of the screw additionally soldering may be appropriate to connect the two parts inseparable. Instead of screwing and subsequent soldering, however, the parts 3 and 4 can also be connected by means of plug connection, bayonet connection or thread.

The driver 5 is in the in Fig. 1 Training shown formed as an annular element which can rotate freely around the drill head shaft 3, 4. In order to be able to entrain the sheath 6 reliably and reliably when the drill head body 2 is introduced into the interior of a borehole, the driver 5 is designed such that it has a plurality of recesses 9 distributed around its outer circumference 10, which in particular Fig. 3 are shown more clearly. Furthermore, the driver is designed so that an outer peripheral region 10 of the driver directed towards the drill head body is contoured, in particular curved. By such a curvature of the outer peripheral portion 10, a kind of tooth 11 is formed, which engages in a corresponding shoulder 12 of the cladding tube 6 and pulls through this engagement in a propulsion in the direction of the arrow 13, the cladding tube 6 in the interior of a borehole. This tooth 11 is thus formed as engaging and / or holding element 11 for cooperating with the drill head 1 sheath 6.

For a secure functioning of the driving of a drill head 1 into the interior of a borehole, the further shaft part 4 or the adapter is formed essentially with two stop parts 14 and 15 arranged parallel to one another. As a result, on the one hand a limitation of the free movement of the driver 5 in the direction out of the borehole through the stop member 14 ensures and on the other hand created by the stop member 15 the possibility that in the further shaft part or the adapter 4, for example, a further adapter is used in the In which case, the abutment surface 15 interacts with a complementary abutment surface of the other adapter to allow a safe power transmission.

In the presentation according to Fig. 2 are the reference numerals of Fig. 1 retain, with in Fig. 2 In addition, passages 16 in the contoured drill head body 2 can be seen, through which passages 16 drill cuttings can be discharged into the interior of the cladding tube 6.

In the presentation of Fig. 3 is the cladding omitted and also in the representation of Fig. 3 the drill head shaft or stub shaft 3 and the adapter or the further shaft part 4 are shown in the screwed state. In Fig. 3 Furthermore, the exact construction of the driver 5 is clearly visible, in particular, the engagement and holding member 11 is clearly visible, which is engageable in a shoulder 12 of the cladding tube 6 into engagement and pull the cladding tube 6 in the interior of the borehole 1 can. By the free rotation of the driver 5, a twisting of the sheath 6 inside the well is avoided with such a procedure with certainty, whereby a longer life of the overall system and in particular an unintentional tearing or destruction of the cladding tube 6 is certainly withheld.

In Fig. 4 a part of the drill head 1 is shown, namely the driver 5 and the further shaft part or adapter 4. The driver 5 is shown in the illustration Fig. 4 analogous to those of Fig. 1 to 3 trained, so that a closer approach to the same does not seem necessary.

The further shaft part or the adapter 4 is in Fig. 4 shown separately from the stub shaft 3 and it can be seen that the end portion, which should look to the shaft part 3, is formed with a thread 17. The thread 17 is in this case connected to a complementary thread in the shaft part 3 and optionally subsequently soldered to provide a permanent bond.

In Fig. 5 is a plan view partially shown in the perspective of the driver or striking star 5. The driver 5 in this case has an annular passage 18 through which the drill head shaft 3 and the further shaft part of the drill head 1 pass and around which shaft of the driver 5 is rotatably arranged. Furthermore, recesses 9 or extensions 19 are formed on the circumference of the driver, distributed at regular intervals. The extensions have a curved outer peripheral region 10, on which, as in connection with Fig. 1 has already been described, a kind of tooth 11 is formed. This number 11 is directed to the drill head 1 and cuts in operation in a corresponding shoulder of the cladding tube 6 a.

Deviating from the representations of Fig. 1 to 3 is also the opposite of the drill head 1 end portion of the adapter 4 formed differently, in particular, it has an education with front teeth, which mesh with a corresponding complementary design of another adapter or a drill rod to unintentional rotation of the drill rod or another adapter , which are both not shown here, with respect to the other shaft part 4 with security hinanzuhalten.

Needless to say, instead of the thread 17 for connection to the shank part 3 of the drill head body 2, for example, a plug connection, a bayonet connection or any other detachable connection can be provided, which can subsequently be made into a non-detachable connection by soldering is not mandatory. Another embodiment of the annular driver, which is freely rotatable on the shaft of the drill head is conceivable, so the number of extending in the radial direction extensions 10 may vary and it can be provided in particular between 4 and 6 of these extensions. It is important that between the extensions 10 passage openings 9 are provided to carry cuttings can. In the same way, the drill head body 2 can be of any desired design, wherein any shape of known drill head or drill head body can be used as long as this drill head or drill head body has a shank 3, in particular stub shank, which can be connected to a further shank part 4.

Claims (15)

1. A drill head (1) comprising a drill head body (2) in which a plurality of drill bits (7) and/or drill templates are fixed in corresponding reception openings, a drill head shaft (3) designed for connection to an element selected from a further shaft portion (4) or an adapter (4), at least one recess (16) for removing cuttings, and optionally at least one opening (8) for applying flushing fluid, characterized in that the drill head shaft (3) is designed as a stump shaft provided with a first connection element for connection to the further shaft portion (4), that an end region directed to the drill head (1), of the substantially tubularly designed further shaft portion (4) or the adapter is configured with a second connection element (17) cooperating with the first connection element of the drill head shaft (3), that an end region facing the drill head (1), of the further shaft portion (4) or the adapter is configured with at least one substantially annular stop member (14), and that a driver (5) capable of being brought into abutment on the substantially annular stop member (14) and surrounding the further shaft portion (4) or the adapter is provided.
2. A drill head (1) according to claim 1, characterized in that the connection elements (17) for connecting the stump shaft (3) to the further shaft portion or the adapter (4) are selected from cooperating thread parts, plug connection parts such as bayonet connection elements, or clamping connection parts.
3. A drill head (1) according to claim 1 or 2, characterized in that a non-detachable fixation of the first and second connection elements (17) to each other by solder is additionally provided.
4. A drill head (1) according to claim 1, 2 or 3, characterized in that the stump shaft (3) is designed in one piece with the drill head body (2), and that the stump shaft (3) is formed of a material different from that of the further shaft portion, or the adapter (4), to be connected thereto.
5. A drill head (1) according to any one of claims 1 to 4, characterized in that the driver (5) is movably, in particular rotationally, disposed on the further shaft portion or the adapter (4).
6. A drill head (1) according to any one of claims 1 to 5, characterized in that the driver (5) comprises a plurality of recesses (9) on its outer circumference (10).
7. A drill head (1) according to any one of claims 1 to 6, characterized in that an outer circumferential region (10) directed to the drill head body (2), of the driver (5) is designed to be contoured, in particular curved.
8. A drill head (1) according to claim 7, characterized in that the contouring of the outer circumference (10) of the driver (5) is designed as an engagement and/or holding element (11) for a starter pipe or a cladding tube (6) optionally cooperating with the drill head (1).
9. A drill head (1) according to any one of claims 1 to 8, characterized in that the shaft portion or the adapter (4) is provided with an internal thread on its end region facing away from the drill head body (5).
10. A drill head (1) according to any one of claims 1 to 9, characterized in that the end region facing away from the drill head (1), of the further shaft portion or the adapter (4) is configured with two substantially parallelly disposed stop members (14,15).
11. A drill head (1) according to claim 7, characterized in that the stop members (15) are designed as substantially annular stop surfaces (14,15) directed substantially normally to an axis of rotation through the drill head body (2), the further shaft portion, or the adapter (4).
12. A method for assembling a drill head (1) comprising a drill head body (2) in which a plurality of drill bits (7) and/or drill templates are fixed in corresponding reception openings, a drill head shaft (3) adapted for connection to an element selected from a further shaft portion or an adapter (4), which comprises at least one recess (16) for removing cuttings and optionally at least one opening (8) for applying flushing fluid, characterized in that a driver (5) surrounding the further shaft portion or the adapter (4) is attached, in particular rotationally attached, to a substantially tubularly designed further shaft portion or adapter (4), that the further shaft portion or the adapter (4), by first and second connection elements (17) provided thereon is detachably fixed in or to a connection element provided on the drill head shaft (3) designed as a stump shaft, that, following the detachable fixing of the further shaft portion or the adapter (4) to the stump shaft (3) of the drill head body (2), a non-detachable connection is formed by welding, soldering or riveting of the further shaft portion or the adapter (4) with the stump shaft (3) of the drill head body (2), and that the non-detachable connection is optionally subjected to a temperature treatment.
13. A method according to claim 12, characterized in that converting into a non-detachable connection is effected by soldering, in particular vacuum soldering.
14. A method according to claim 12 or 13, characterized in that a thermal treatment, in particular tempering, is performed after soldering.
15. A method according to claim 12, 13 or 14, characterized in that the temperature and/or the time of tempering are selected such that a structural change is caused during tempering in the further shaft portion or the adapter (4), and that the driver (5) and the drill head body (2) are formed of a material different from that of the further shaft portion or the adapter (4) .

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