Rotary head unit for a rotary head tool, rotary head tool and method for performing a machining operation on an opening of a workpiece

Abstract

Rotary head unit (1) for a rotary head tool (2), wherein the rotary head unit (1) comprises: - comprising a drive cylinder (3): - a hollow-circle cylindrical coupling body receptacle (4), - a drive element (7) arranged in a rotationally fixed manner with respect to the coupling body receptacle (4), which extends from an inner circumferential wall (5) of the coupling body receptacle (4) at least to a longitudinal central axis (8) of the coupling body receptacle (4), - a circular cylindrical coupling body (10) arranged in the coupling body receptacle (4), which is movably mounted along a base surface (6) of the coupling body receptacle (4) and has: - an outer radius (16) which is smaller than an inner radius (19) of the coupling body receptacle (4) by a specified tolerance field radius (17), - a first coupling body disk (11) and a second coupling body disk (12), between which the drive element (7) is arranged, wherein the second coupling body disk (12) is rotationally fixed to or connectable with a rotary tool effector (13), - a driver body (14) which extends parallel to a longitudinal center axis (15) of the coupling body (10), wherein the coupling disks (11, 12) are connected to each other at their edges in a rotationally fixed manner by means of the driver body (14).

Description

[0001] The present invention relates to a rotary head unit for a rotary head tool and a rotary head tool with such a rotary head unit, as well as a method for performing a machining operation on an opening of a workpiece using such a rotary head tool.

[0002] Misalignment of assembly parts prior to automated or robot-assisted machining processes, particularly the automated screwing of two components, results from process, equipment, and individual part tolerances. For example, components with pre-installed rubber bearings, springs, and flexible suspensions can only be automatically brought into contact with the main assembly (e.g., a car body) for screwing within a relatively large tolerance range in the equipment. Rigidly programmed robots in conjunction with standard screwdrivers without tolerance compensation would move to the target screwing coordinates of the screwing point with repeatable accuracy. If the screw axis does not fully align with the screw bushing of the assembly part at the targeted position, incorrect screwing occurs at the screwing point (the screw does not engage or jams in the first thread).Using special screws or nuts with centering cones, the components to be screwed together can be aligned with each other during the screwing process; however, the threaded bushing must first be reliably hit and screwed in by the robot screwdriver within the expected tolerance range with the screw during the "thread search" with complete tolerance compensation.

[0003] In automated screwdriving processes (for example, in automotive assembly, such as when tightening a strut), robot-guided screwdrivers with technically limited tolerance compensation are used. The entire screwdriver is mounted on a floating bearing. Tolerance compensation occurs during the thread search while the magnetically held bolt is being tightened. This requires compensating for or overcoming the high inertial forces of the screwdriver, which weighs several kilograms, and the bearing friction of the screwdriver's floating mount on a base frame. The acceleration reaction forces and the opposing forces from bearing friction during tolerance compensation result from the large mass of the entire floating screwdriver and often cannot be reliably overcome by the bolt being held in the socket with a low force. This can lead to incorrect tightening.Therefore, the floating bearing of the entire screw technology on the robot arm must be blocked with electromagnetic brakes during the robot's movement and swiveling processes, requiring considerable technical effort.

[0004] In the specific case of strut mounting, the situation is further complicated by the fact that, for economic reasons, the strut alignment pins are cast from soft aluminum onto the strut bearing, resulting in an unfavorable material and friction pairing between the steel body and the strut. Due to this unfavorable friction pairing, the alignment pins can seize on a stamping burr in the body shell, leading to incomplete component alignment before bolting. Furthermore, a technically flawed degree of freedom in the strut mounting reduces the precision of the strut's pre-positioning relative to the body during automated assembly. Specifically, an excessively large round hole in the strut plate of the body (instead of a precisely aligned elongated hole with a tight width fit) results in an inconsistent component mounting of the strut onto the body.This can lead to unwanted pivoting of the strut before assembly, further increasing the tolerance range in the automated assembly process.

[0005] These problems occur analogously in other automatic or robot-assisted machining processes, in which an attack element of a tool must be used to approach a point on a workpiece surface as precisely as possible and then penetrate the workpiece translationally, i.e. in a straight feed direction, such as in countersinking, thread cutting, drilling, etc.

[0006] DE 10 2018 126 250 A1 discloses an assembly technique for the simultaneous assembly of several subassemblies using a robot. The disclosed assembly tool comprises a carrier, at least two gripping units in which a subassembly can be received in a gripping position, a delivery device for delivering the gripping units, and a floating bearing for at least one gripping unit. The assembly technique also comprises a force-sensitive robot with the disclosed assembly tool and an assembly method.

[0007] Furthermore, DE 38 17 671 A1 discloses an automatic screw-in device for spark plugs into the spark plug bores of internal combustion engines. An industrial robot grasps the spark plug and inserts it into a socket. The socket is articulated and held approximately in the axial direction of the spark plug bore by means of a spring assembly. This bore serves as a guide bore for the socket, so that a simple feed motion guides the spark plug precisely into the thread of the receiving bore. A further spring assembly is provided to allow screw-in in another installation position, perpendicular to the first.

[0008] Furthermore, DE 10 2020 100 435 B4 discloses a radially compliant robot tool comprising: a housing; a longitudinal shaft extending from the housing and defining a longitudinal axis in a centered ground state; a locking rod located transversely to the longitudinal axis, wherein the locking rod is movable between a first position in which the longitudinal shaft has a radial compliance from the longitudinal axis over 360 degrees, and a second position in which the locking rod restricts the longitudinal shaft with respect to a compliance from the longitudinal axis to only one radial direction.

[0009] The object of the present invention is to compensate for positional and / or manufacturing tolerances of workpieces during their machining as efficiently as possible.

[0010] The area to which US 2016 / 0279798 A1 generally refers includes fastening and, in particular, automatic alignment correction during fastening.

[0011] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, across categories and embodiments as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0012] According to the invention, a rotary head unit for a rotary head tool is proposed. The rotary head unit comprises a drive cylinder that includes a hollow-circular cylindrical coupling body receptacle. Furthermore, a rotary head tool is proposed that includes the rotary head unit and a drive unit (for example, an electric machine), wherein the drive cylinder and the drive unit are rotationally fixed to one another. For example, a drive shaft of the drive unit and the drive cylinder can be connected directly or indirectly, for example, by means of one or more gear stages. The drive cylinder also comprises a drive element arranged rotationally fixed with respect to the coupling body receptacle, which extends from an inner circumferential wall of the coupling body receptacle at least to a longitudinal center axis of the coupling body receptacle or beyond.The rotary head unit further comprises a circular cylindrical coupling body arranged in the coupling body receptacle, which is movably mounted along a base surface of the coupling body receptacle. In other words, the coupling body is received in the coupling body receptacle and rests on the base surface of the coupling body receptacle. The coupling body is movable within the coupling body receptacle by being able to slide on the base surface. The coupling body is designed, for example, as a straight circular cylinder, although a different shape, such as a prismatic shape, is not excluded. Furthermore, the coupling body has an outer radius that is smaller than the inner radius of the coupling body receptacle by a predetermined tolerance radius. This enables the aforementioned movement of the coupling body within the coupling body receptacle.The tolerance radius is specified during the design of the coupling body mount and the coupling body itself, taking into account the intended use of the rotary head unit or the rotary head tool incorporating the rotary head unit. Furthermore, the coupling body comprises a first coupling body disk and a second coupling body disk, with the drive element positioned between the coupling body disks. The second coupling body disk is rotationally fixed to a rotary tool effector or can be connected to it. This means that the second coupling body disk can have a connecting device, such as a chuck, by means of which the rotary tool effector can be rotationally fixed to the second coupling body disk. It is also conceivable that the second coupling body disk and the rotary tool effector are formed integrally or connected by force-fit, form-fit, and / or material-fit.Any tool effector that rotates around its longitudinal center axis to perform its function can be considered a rotary tool effector. For example, a rotary tool effector can be designed as a socket, screwdriver, drill, external or internal thread cutter, honing tool, reamer, milling cutter, countersink, etc. The coupling body also includes a drive element that extends parallel to a longitudinal center axis of the coupling body, with the coupling discs being rotationally fixed to each other at their edges by means of the drive element.

[0013] In a method according to the invention, a machining operation is performed on an opening of a workpiece using the rotary tool – in particular using a robot system comprising a robot, especially an articulated robot arm. First, an effector point of the rotary tool effector, which is rotationally fixed to the second coupling body disk, is brought to a predetermined target coordinate such that a longitudinal center axis of the opening intersects a circular tolerance field having the tolerance field radius. Then, the rotary tool is moved in a straight feed direction, whereby a tip of the rotary tool effector or a tip of a semi-finished product coupled to the rotary tool effector (for example, a screw) slides off an edge of the opening, thereby deflecting the coupling body from the center of the coupling body receptacle so that the effector point falls onto the longitudinal center axis of the opening.During or subsequently, the drive cylinder is driven by the drive unit, and consequently the workpiece or its opening is machined, for example, by drilling, countersinking, threading, inserting a screw, etc. The effector point is a predefined point on the rotary tool effector, such as the center point of a socket, the tip or center point of a screwdriver blade, the tip of a cutting edge on a drill, tap, honing or reaming tool, milling cutter, countersink, etc. Furthermore, the effector point can be formed by a tool center point of the robot system, where the rotary tool is attached to an end effector of the robot. In general, the effector point is the point relevant for the spatial movement and function of the rotary tool effector.In particular, the effector point lies on the longitudinal center axis of the drive cylinder or the coupling body mount. Positional and / or manufacturing tolerances of the workpiece are compensated for particularly efficiently and initially without additional control effort thanks to the floating mounting of the coupling body in the coupling body receptacle. This allows for consistently high quality to be achieved particularly easily and with minimal effort, especially in automated, for example, robot-assisted, machining processes.

[0014] Another possible embodiment provides for a radius-parallel segment that intersects the longitudinal center axis of the coupling body perpendicularly and by which a longitudinal center axis of the drive body and an outer edge point of the coupling body are spaced apart, to be 1.3 times the inner radius of the coupling body receptacle or more. It has proven particularly advantageous if said segment is 1.5 times the inner radius of the coupling body receptacle. This ensures that the lever arm acting on the coupling body from the longitudinal center axis of the drive cylinder does not become too small during a full revolution.

[0015] In a further possible embodiment, the rotary head unit has a centering device which, in its relaxed state, holds the coupling body centrally in the coupling body receptacle and, in its tensioned state, drives the coupling body to the center of the coupling body receptacle. The centering device has a spring element receptacle formed in / on the drive cylinder, in which a spring element is seated. This spring element tensions a centering element parallel to the longitudinal center axis of the coupling body receptacle in the direction of the coupling body, which has a straight-conical centering element receptacle whose base circle radius is larger than the tolerance field radius. The centering element is, for example, a ball or a pin whose end facing the coupling body is rounded.Alternatively or additionally, the centering device features a leaf spring arrangement, the leaf springs of which are arranged in the coupling body receptacle and fixed to the coupling body or to the inner circumferential wall of the coupling body receptacle. This reliably centers the coupling body for reuse in the coupling body receptacle.

[0016] According to another possible embodiment, the drive element is designed as an elongated support that extends through the coupling body receptacle only as far as its longitudinal center axis. This also includes embodiments in which the support extends into a portion of the longitudinal center axis of the coupling body receptacle, i.e., passes through more than half of the receptacle, but not completely. In this way, the drive cylinder can be manufactured with a particularly small amount of material. Alternatively, the drive element or support can extend completely through the coupling body receptacle, i.e., protrude from / protrude from the inner wall of the coupling body receptacle and terminate on / within the inner wall opposite. This makes the drive cylinder particularly stable.

[0017] According to a possible further development, if the support completely traverses the coupling body receptacle, a longitudinal section of the support is point-symmetric with respect to a point of symmetry, which is formed by an intersection point where the longitudinal center axis of the coupling body perpendicularly intersects the longitudinal section surface. As another possible embodiment provides, the support can be designed as a completely straight support along its longitudinal direction, which makes the support particularly easy to manufacture, or it can have a kink and / or a bend along its longitudinal direction. In the latter case, the centering device for centering the coupling body in the coupling body receptacle can be omitted. A brief angular acceleration of the drive cylinder causes the drive body to slide on the drive element itself, even without a centering device.the carrier exhibiting the kink and / or bending and is centered in the coupling body receptacle due to the shape of the drive element / carrier.

[0018] In another possible embodiment, the carrier or drive element has a rectangular cross-sectional area, which, in combination with a straight cylindrical drive body, is advantageous because it creates a linear contact between the carrier and the drive element. Alternatively, the carrier or drive element has a circular cross-sectional area. With a drive body that has a spherical cross-section, this also results in a linear contact between the carrier and the drive element. A linear contact between two sliding elements is preferable to a point contact because the force between the elements is not transmitted at a single point, i.e., over an extremely small contact area, but rather over a larger contact area. Due to the lower surface pressure between them, the elements are subjected to less stress.

[0019] Another possible embodiment involves the coupling discs and the drive body being materially bonded together, particularly as a single piece. This allows for a surface contact between the straight-circle cylindrical support or drive element and the drive body. The drive body can have a round, trough-shaped portion whose contour corresponds to a straight-circle cylindrical support. Due to the even lower surface pressure between them, the support and the drive body are subjected to even less stress. A coupling body designed in this way can be manufactured, for example, using a finger milling cutter or an additive manufacturing process (such as selective laser sintering).

[0020] An alternative embodiment to the carrier-type drive element provides that the drive element is designed as an elongated slot (i.e., as a material-free volume) extending from the inner circumferential wall of the coupling body receptacle to the longitudinal center axis of the coupling body receptacle. The elongated slot completely penetrates a base of the drive cylinder that has the same surface area as the coupling body receptacle. The coupling body disks are spaced apart from each other along the longitudinal center axis of the coupling body receptacle via the base, with the drive element extending through the elongated slot. This simplifies the manufacture of the drive cylinder. If a centering device is provided, it is arranged off-center.

[0021] An alternative to the coupling body discs being bonded together involves the drive element connecting the coupling body discs being designed as a bolt manufactured separately from one or both of the coupling body discs. The coupling body discs are then connected to each other by means of the bolt via a force-fit, form-fit, and / or material-fit connection, for example, by mortising the bolt into the two coupling body discs, etc. This design also includes coupling bodies in which one of the two coupling body discs and the bolt are formed integrally or otherwise bonded together. This is mandatory for embodiments in which the drive element is designed as the elongated hole, at least if the drive cylinder is manufactured in one piece or monolithically. This is because the bolt must be inserted through the elongated hole to assemble the rotary head unit.For embodiments in which the drive element is designed as the carrier, the coupling body can be designed as a single piece / monolithic or in multiple parts.

[0022] According to a further embodiment, the rotary head unit has a drive unit that is rotationally fixed to the drive cylinder and comprises a spur gear ring, particularly in the form of a bevel gear ring, and / or a clamping pin. The clamping pin, which is rotationally fixed to the drive cylinder, can, for example, be clamped in a chuck of a machine tool. The resulting ease of interchangeability makes the rotary head unit particularly versatile. The drive cylinder, as part of the rotary head tool, can be driven via the spur gear ring, which is rotationally fixed to the drive cylinder. For this purpose, a drive train of the drive unit includes, for example, a drive spur gear that meshes with the spur gear ring of the rotary head unit.If the spur gear ring is designed as the bevel gear ring, it is advantageously easy to design the rotary head tool having the rotary head unit as an angled tool, for example as an angle screwdriver or angle drill, etc.

[0023] In a possible further development of the rotary tool, which includes the rotary head unit, it incorporates an electronic control unit and sensors. The electronic control unit can, for example, be designed as part or a module of a robot controller within the robot system, with the rotary tool mounted on an end effector. The sensors are configured to detect the position of the longitudinal center axis of the coupling body relative to an effector point of the rotary tool effector, which is rotationally fixed to the second coupling body disk, and to provide this data (i.e., a data set characterizing the position) to the control unit.Since the effector point lies on the longitudinal center axis of the coupling body mount, determining the relative position of the coupling body's longitudinal center axis to the effector point reveals how far and in which direction(s) the coupling body's longitudinal center axis deviates from the coupling body mount. For this purpose, the sensor system, located, for example, in / on a housing of the rotary head tool in which the rotary head unit is rotatably mounted, incorporates mechanical, optical, magnetic, electrical, or acoustic distance sensors. These sensors include, for example, a first distance sensor for determining the position of the coupling body's longitudinal center axis with respect to a first spatial direction (e.g., the X-direction) and a second distance sensor for determining the position of the coupling body's longitudinal center axis with respect to a second spatial direction (e.g., the Y-direction).Furthermore, the control unit is configured to spatially adjust the drive cylinder in response to a detected deviation between the longitudinal center axes, so that the longitudinal center axes (re)align. To achieve this, the control unit initiates, for example, a corresponding movement of the robot's kinematics. Specifically, the control unit adds the X and Y deviations of the longitudinal center axis of the coupling body to the current position coordinate of the effector point. In other words, the effector point is moved by precisely the vector that, before the adjustment, originates at the effector point and terminates at the longitudinal center axis of the coupling body in the XY plane.By simply adding up the deviations, a pose of the robot kinematics of the robot system can be adjusted particularly easily in order to bring the longitudinal center axes of the coupling body holder and the coupling body back into overlap and thereby compensate for manufacturing and / or positional tolerances of the opening of the workpiece.

[0024] Alternatively or additionally, the control device is configured to adjust the drive speed of the drive unit in response to any deviation of the coupling body's longitudinal center axis from the effector point, such that a rotational speed profile of the drive cylinder causes the coupling body to rotate about its longitudinal center axis at a constant speed. This is because if the coupling body is positioned off-center in the coupling body receptacle by being held externally, for example, when the tip of the rotary tool effector is already engaged in the workpiece opening, a constant drive speed of the drive unit would lead to non-uniform rotation of the coupling body and, consequently, of the rotary tool effector; the rotation of the rotary tool effector would exhibit a wow and flutter.Considering the rotation of a fixed point on the drive cylinder, a sinusoidal angular pattern results for this point, assuming a constant angular velocity over time. If the coupling element is positioned centrally within its receptacle (its longitudinal center axis coincides with the center axis of the receptacle), the angular velocity of the drive cylinder and the angular velocity of the coupling element are equal. This means that a sinusoidal angular pattern also results for a fixed point on the coupling element. However, if the coupling element is disengaged from its central position (its longitudinal center axis and the center axis of the receptacle diverge), the angular pattern of the point on the coupling element deviates from a sinusoidal shape because the coupling element does not rotate at a constant speed when the drive cylinder rotates uniformly.The control device allows the drive unit to be controlled in such a way that the drive cylinder rotates at a deliberately non-uniform rotational speed, so that the eccentrically arranged coupling body rotates at a constant rotational speed.

[0025] In a possible further development of the process, the sensor system of the rotary tool thus detects the position of the coupling body's longitudinal center axis relative to the effector point – i.e., relative to the longitudinal center axis of the coupling body receptacle – and provides this information to the control unit. The control unit then controls the rotary tool such that, if the longitudinal center axis of the coupling body and the effector point deviate from each other, the drive cylinder is spatially adjusted so that the effector point is moved to the longitudinal center axis of the coupling body, thus aligning the longitudinal center axis of the coupling body and the longitudinal center axis of the coupling body receptacle. Alternatively or additionally, the control unit can adjust the rotary tool upon detecting a deviation of the coupling body's longitudinal center axis from the effector point.controlled from the longitudinal center axis of the coupling body receptacle in such a way that the drive speed of the drive unit is controlled in such a way that a rotational speed profile of the drive cylinder causes the coupling body to rotate about its longitudinal center axis at a constant rotational speed.

[0026] By spatially adjusting the drive cylinder and controlling the drive speed, a measure is taken to ensure constant rotation of the coupling body and, consequently, of the rotary tool effector rigidly attached to it. It is also conceivable to take into account the determined deviation of the coupling body's longitudinal center axis from the effector point of a current rotary tool operation, such as a screwing or drilling process, etc., for a subsequent rotary tool operation. In this way, the deviation from the preceding rotary tool operation can be factored into the target coordinate for the subsequent rotary tool operation to minimize the coupling body's disengagement from its central position.Alternatively or additionally, it can be provided that, during the subsequent use of the turning tool, the control unit is used to rotate the drive unit at the non-uniform rotational speed determined for the previous turning tool use, before the deviation of the coupling body's longitudinal center axis from the effector point is determined. This ensures that the eccentrically positioned coupling body rotates with a less pronounced synchronous fluctuation. In this way, the need for readjustment of the robot kinematics and / or the drive speed for the subsequent turning tool use can be minimized.

[0027] Further features of the invention may become apparent from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0028] The drawing shows in Fig. 1 along the cutting plane II (see Fig. 2) Sectional view of a rotary head unit of a rotary head tool, Fig. 2 one along the cutting plane II-II (see Fig. 1) cropped view of the in Fig. 1 rotary head unit shown, Fig. 3- Fig. 8 one along the section plane III-III (see Fig. 1) Sectional view of different designs of a drive cylinder of the rotary head unit, Fig. 9 one along the section plane IX-IX (see Fig. 7) Sectional view of the coupling body, Fig. 10 one along the cutting plane XX (see Fig. 8) Sectional view of the coupling body, Fig. 11 one along the section plane XI-XI (see Fig. 12) Sectional view of a rotary head unit in an alternative design, Fig. 12 one along the cutting plane XII-XII (see Fig. 11) sectional view of the Fig. 11 shown rotary head unit, Fig. 13, Fig. 14 each a partially cutaway view of the rotary head unit clamped in a chuck by means of a clamping pin with a countersink as a rotary tool effector, Fig. 15 one along the cutting plane XV-XV (see Fig. 16) Sectional view of the rotary head tool comprising the rotary head unit, Fig. 16 one along the section plane XVI-XVI (see Fig. 15) sectional view of the in Fig. 15 rotary head tools shown, Fig. 17 one along the cutting plane XVI-XVI (see Fig. 15) Sectional and partial view of the rotary head tool during its intended use, Fig. 18- Fig. 22 To illustrate a process in which a machining operation is carried out on an opening of a workpiece using the rotary head tool, two rotary head tools are shown which are used to screw together two workpieces.

[0029] The following section describes a rotary head unit 1 for a rotary head tool 2, the rotary head tool 2 itself, and a method in which a machining operation is performed on an opening of a workpiece using the rotary head tool 2. Identical or functionally equivalent elements in the figures are designated with the same reference numeral. For ease of reference, the following description uses a coordinate system shown in the figures. This coordinate system is, for example, a base coordinate system of a robot, in particular an articulated robot, or a robotic system.

[0030] Fig. 1 shows one along the cutting plane II (see Fig. 2) Sectional view of the rotary head unit 1 of the rotary head tool 2, which was first introduced in Fig. Figure 15 shows the rotary head unit 1. The rotary head unit 1 has a drive cylinder 3, which has a hollow cylindrical coupling body receptacle 4, bounded by an inner circumferential wall 5 and a base surface 6. The drive cylinder 3 also has a drive element 7, which is rotationally fixed relative to the coupling body receptacle 4 and extends from the inner circumferential wall 5 at least to a longitudinal center axis 8 of the coupling body receptacle 4 (or of the drive cylinder 3) or beyond the longitudinal center axis 8 of the coupling body receptacle 4. It can be seen that the drive element 7, when designed as a support 9 as in this case, is arranged parallel to the flat base surface 6. A circular cylindrical coupling body 10 is arranged in the coupling body receptacle 4 and is movably mounted along or by means of the base surface 6.The coupling body 10 has a first coupling body disk 11 and a second coupling body disk 12, between which, as in . Fig. Figure 1 shows the drive element 7, here the carrier 9, in which it is arranged. The second coupling body disk 12 and a rotary tool effector 13, explained here using the example of a socket wrench with internal hexagon, can be connected to each other, for example by means of a chuck (see Figure 1). Fig. 14). In the present case, the second coupling body disk 12 and the rotary tool effector 13 are materially bonded to one another, in particular formed in one piece. Furthermore, the coupling body 10 has a drive body 14 which is Fig. 1 is concealed by support 9 and extends parallel to a longitudinal center axis 15 of the coupling body 10. It is further in Fig. Figure 1 shows that the coupling body disks 11, 12 are connected to each other at their edges in a rotationally fixed manner by means of the drive body 14. In this example, the coupling body disks 11, 12 and the drive body 14 are connected to each other in a rotationally fixed manner by the drive body 14 being connected on one side to the first coupling body disk 11 and on the other side to the second coupling body disk 12. In particular, the coupling body disks 11, 12 and the drive body 14 are formed integrally with each other.

[0031] Fig. 2 shows one along the section plane II-II (see Fig. 1) cropped view of the in Fig. 1 rotary head unit 1 shown, where it can be seen that both coupling body disks 11, 12 have an outer radius 16 which is smaller than an inner radius 19 of the coupling body receptacle 4 by a predetermined tolerance field radius 17 of a circular disk-shaped tolerance field 18. In Fig. Figure 2 further shows a radius-parallel line segment 20 that intersects the longitudinal center axis 15 of the coupling body 10 perpendicularly, and along which a longitudinal center axis 21 of the drive body 14 and an outer edge point 22 of the coupling body 10 are spaced apart. The line segment 20 lies in an XY plane in which the planar base 6 also lies. The length of the line segment 20 is 1.3 times the inner radius 19 of the coupling body receptacle 4 or more, for example, 1.5 times.

[0032] In Fig. 1 and in Fig. Figure 2 further shows that the rotary head unit 1, according to the present example, has a centering device 23 which, in its relaxed state, holds the coupling body 10 centrally in the coupling body receptacle 4 and, in its tensioned state, drives the coupling body 10 into the center of the coupling body receptacle 4. The centering device 23 has a spring element receptacle 24, which is formed in / on the drive cylinder 3 and in which a spring element 25, here designed as a helical spring, is seated. This tensions a centering element 26, which can be designed as a ball or as a pin, parallel to the longitudinal center axis 8 of the coupling body receptacle 4 in the direction towards the coupling body 10. The coupling body 10 has a straight-conical centering element receptacle 27, the base circle radius 28 of which is larger than the tolerance field radius 17.Alternatively, or – as provided in this example – additionally, the centering device 23 has a leaf spring arrangement 29, the leaf springs 30 of which are arranged in the coupling body receptacle 4 and fixed to the coupling body 10 or to the inner circumferential wall 5 of the coupling body receptacle 4. The leaf springs 30 can each be straight or odd / curved.

[0033] Fig. 3 to Fig. 8 show a section along the cutting plane III-III (see Fig. 1 as well as Fig. 9 and Fig. 10) Sectional view of different designs of the drive cylinder 3 of the rotary head unit 1. It is particularly evident in these figures that the drive element 7 can be designed as the elongated support 9, which extends completely (see Fig. 4, Fig. 6, Fig. 7, Fig. 8) or only up to the longitudinal center axis 8 of the coupling body receptacle 4 (see Fig. 3, Fig. 5) extends through these. Furthermore, it can be seen that the coupling body 10 can have two drive bodies 14, see Fig. 4, Fig. 6, Fig. 7, Fig. 8, wherein the two drive bodies 14 are exactly opposite each other, that is, spaced 180° apart. Furthermore, it can be seen - see Fig. 3 to Fig. 6 - that the beam 9 can exhibit a kink 31 or a bend 32 along its longitudinal direction, that is, along its central fiber. Furthermore, it is understood that the beam 9 can exhibit two or more kinks 31 or bends 32. It is also conceivable that a beam 9 exhibits both a kink 31 and a bend 32. From Fig. 8 and Fig. It can be seen from point 9 that the carrier 9 can alternatively be completely straight, as is also the case in Fig. 1 and Fig. 2 is shown. From Fig. 4, Fig. 6, Fig. 7 and Fig. Figure 8 also shows that when the support 9 completely traverses the coupling body receptacle 4, it has a longitudinal section figure which is point-symmetric with respect to a symmetry point 33, which marks an intersection point at which the longitudinal center axis 8 of the coupling body receptacle 4 perpendicularly pierces the longitudinal section surface.

[0034] Fig. 9 shows one along the section plane IX-IX (see Fig. 7) sectional view of the in Fig. 7 coupling body 10 shown, and Fig. 10 shows one along the section plane XX (see Fig. 8) sectional view of the in Fig. 8 coupling body shown 10. From a summary of the Fig. 7 with Fig. It can be seen from Figure 9 that the support 9 has a rectangular, for example square, cross-sectional area, while the respective drive body 14 is formed as a straight circular cylinder, which means that the drive body 14 and the respective support 9 are in line contact with each other. The drive body 14 connecting the coupling body disks 11, 12 is, for example, designed as a bolt 34 manufactured separately from one or both of the coupling body disks 11, 12. Another variant, in which the coupling body disks 11, 12 and the drive body 14, as also in Fig. 1 shown, formed in one piece together, is in Fig. 8 and Fig. Figure 10 shows that the drive body 14 has a round, trough-shaped portion 35, and the carrier 9 is designed as a shaft or a straight circular cylinder, with the radius of the shaft or carrier 9 and the radius of the round, trough-shaped portion 35 of the drive body 14 being equal. In this case, the carrier 9 thus has a round cross-sectional area. This allows for planar contact between the carrier 9 or drive element 7 and the drive body 14. A coupling body 10 designed in this way can be manufactured, for example, using a finger milling cutter or an additive manufacturing process (such as selective laser sintering).

[0035] Fig. 11 shows one along the section plane XI-XI (see Fig. 12) Sectional view of the rotary head unit 1 in alternative design, in which the drive element 7 is designed as an elongated hole 36 (i.e. as a material-free volume). Fig. 12 shows one along the section plane XII-XII (see Fig. 11) sectional view of the Fig. The rotary head unit 1 shown in Figure 11. The elongated hole 36 extends from the inner circumferential wall 5 of the coupling body receptacle 4 to the longitudinal center axis 8 of the coupling body receptacle 4 and completely penetrates a base 37 of the drive cylinder 3, which has the base surface 6 of the coupling body receptacle 4. The coupling body disks 11, 12 are spaced apart from each other along the longitudinal center axis 8 of the coupling body receptacle 4 via the base 37, with the drive body 14 extending through the elongated hole 36 along the longitudinal center axis 8 of the coupling body receptacle 4.

[0036] In Fig. 1 and Fig. 11 can further be seen that the rotary head unit 1 according to the present example has a drive device 38 which is non-rotatably connected to the drive cylinder 3 and which has a spur gear ring 39, here designed as a bevel gear ring. Fig. 13 and Fig. Figures 14 each show a partially cutaway view of the rotary head unit 1, whose drive unit 38 – alternatively or additionally to the spur gear ring 39 – has a clamping pin 40 by means of which the rotary head unit 1 is clamped in a chuck 41, shown here as a drill chuck. It can also be seen that the rotary tool effector 13 is designed as a countersink, with the countersink and the two coupling body disks 12 being directly and rotationally fixedly connected to each other. With regard to Fig. 11 shows that the countersink (or more generally the rotary tool effector 13) and the two coupling body disks 12 can be indirectly connected to each other in a rotationally fixed manner, for example by means of a further clamping chuck 42.

[0037] Fig. 15 shows a section along the cutting plane XV-XV (see Fig. 16) Sectional view of the rotary head tool 2 comprising the rotary head unit 1, showing that the drive cylinder 3 and a drive unit 43 of the rotary head tool 2 are rotationally fixed to one another by means of a drive spur gear 44 of the drive unit 43, which is designed here as a bevel gear, and the spur gear ring 39 of the rotary head unit 1 meshing together. It is shown that the rotary tool effector 13 can be designed as a screw socket, here with an internal hexagon geometry. For clarification, in Fig. Figure 15 indicates a screw 45 with a hexagonal head 46, which is held in the socket. The socket may have a retaining magnet 47, by means of which a magnetizable screw can be secured against falling out of the socket. Fig. 16 shows one along the section plane XVI-XVI (see Fig. 15) sectional view of the in Fig. 15 rotary head tools shown 2. From a summary of the Fig. 15 and Fig. Figure 16 shows that the rotary head tool 2 has a sensor system 48 comprising two distance sensors 49, 50, both of which are arranged in / on a housing 51 of the rotary head tool 2, in which the rotary head unit 1 is rotatably mounted. The rotary head tool 2 also has a control unit (not shown). The sensor system 48 is configured to detect the position of the longitudinal center axis 15 of the coupling body 10 relative to an effector point 56 of the rotary tool effector 13, which is non-rotatably connected to the second coupling body disk 12 – that is, relative to the longitudinal center axis 8 of the coupling body receptacle 4 – and to provide this information to the control unit. Fig. The distance sensor 16, labeled 49, is configured to detect a deviation of the longitudinal center axis 15 from the longitudinal center axis 8 along the X-axis, and the distance sensor 50 is configured to detect a deviation of the longitudinal center axis 15 from the longitudinal center axis 8 along the Y-axis. The control unit is configured to determine the deviation of the longitudinal center axes 15 from the effector point 56 and, based on the detected deviation, to spatially adjust or readjust the drive cylinder 3 so that the longitudinal center axes 8 and 15 (re)align. For this purpose, the control unit initiates, for example, a corresponding movement of the robot kinematics of a robot on whose end effector the rotary head tool 2 is mounted. By moving the robot kinematics in this way, the effector point 56 is moved by exactly the vector that, before the adjustment, is based at the effector point 56 and ends in the XY plane at the longitudinal center axis 8 of the coupling body 10.The electronic control unit can, for example, be designed as part or a module of the robot's control system. Alternatively or additionally, the control unit is configured to control the drive speed of the drive unit 43 in response to the deviation of the aforementioned longitudinal center axes 8, 15, such that a rotational speed profile of the drive cylinder 3 causes the coupling body 10 to rotate about its longitudinal center axis 15 at a constant rotational speed. Thus, the drive unit 43 can be selectively controlled by the control unit so that the drive cylinder 3 rotates at a non-uniform rotational speed, resulting in the eccentrically arranged coupling body 10 rotating at a constant rotational speed.

[0038] In Fig. 17a is along the section plane XVI-XVI (see Fig. Figure 15) shows a sectioned and partial view of the rotary head tool 2 during its intended use. In starting position A, the longitudinal center axes 8 and 15 coincide because the coupling body 10 is arranged centrally in the coupling body receptacle 4. In position B, the drive cylinder 3 has not yet been rotated, but the coupling body 10 has been deflected from its central position, so that the longitudinal center axis 8 of the coupling body 10, on which the effector point 56 lies, and the longitudinal center axis 15 of the drive cylinder 3 or the coupling body receptacle 4 diverge by a deviation 52. The deviation 52 arises, for example, because a longitudinal center axis of a screw opening, into which a screw located in the socket is to be screwed, is offset by the deviation 52 relative to the longitudinal center axis 8 due to manufacturing tolerances or positional tolerances of a workpiece containing the screw opening.By driving the drive cylinder 3, the coupling body 10 is rotated, as shown in . Fig. 17a in position C as well as in Fig. Figure 17b is shown in position D. It can be seen that the drive cylinder 3 drives the drive body(s) 14 by the drive element 7, shown here as the carrier 9, coming into contact with the respective drive body 14 and being rotated further. Fig. Figure 17b shows position E of the rotary tool 2, where it can be seen that the socket or the rotary tool effector 13 is re-centered by spatially repositioning the drive cylinder 3. This is achieved by moving the rotary tool 2 or its housing 51 by precisely a vector characterizing the deviation 52. The housing 51, and consequently the drive cylinder 3, are thus moved in sync with the coupling body 10 or the rotary tool effector 13, such that the longitudinal center axes 8 and 15 coincide again. During or after this, the drive cylinder 3 is driven (further) so that the socket continues to rotate, with the longitudinal center axes 8 and 15 remaining in contact. This is shown in position F.

[0039] The method, in which a machining operation is carried out at an opening 53 of a workpiece using the rotary head tool 1, is described with reference to the Fig. 18 to Fig. 22 is explained using the example of bolting a strut mount 54 (workpiece) to a motor vehicle body 55. First, the workpiece or strut mount 54 is brought into the working area of ​​the rotary head tool 2. In this example, the rotary head tool 2 is flanged to a distal end member of the robot mentioned above (not shown). It is in Fig. It can be seen that the workpiece / strut mount 54 deviates from a desired target position; it is at an angle relative to the body. The effector point 56 of the rotary tool effector 13, which is rotationally fixed to the second coupling body disk, is brought to a predetermined target coordinate such that a longitudinal center axis 57 of the opening 53 (here an internal threaded opening of a screw bushing) intersects the tolerance field 18, which has the tolerance field radius 17. The effector point 56 can, for example, be defined or specified as a point 65 on a screw 45 temporarily fixed in the socket. Furthermore, the effector point 56 can be defined / specified as a point located elsewhere, such as the center point of the socket (see figure). Fig. 15, Fig. 16. In any case, the control device is provided with a position of the screw tip. In this example, screw 45 is a special screw with a conical centering tip 65, as shown in Fig. 18 to Fig. Figure 22 shows that the centering tip of screw 45 enables automated insertion of the screw 45 within the tolerance field with the core diameter of the screw 45 into an internal thread diameter of the opening 53 or the internal thread opening. Fig. Figure 19 shows how the rotary head tool 2 is moved in a straight feed direction (here, exclusively in the Z direction), whereby a tip 65 of the screw 45 slides off an edge of the opening 53, causing the coupling body 10 to be deflected from the center of the coupling body receptacle 4 such that the effector point 56 falls onto the longitudinal center axis 57 of the opening 53, which in Fig. 19 is indicated by the dotted lines 61. A centering tip / point 65 with the sharpest possible angle and a low coefficient of friction between the tip 65 and the internal thread of the internal threaded opening reduce forces that would prevent the tip 65 or centering tip from sliding on the edge of the opening 53 – and consequently prevent the coupling body 10 from disengaging from the center of the coupling body receptacle 4. During or subsequently, the drive cylinder 3 is driven by the drive unit 43, and consequently the strut bearing 54 or its opening 53 is machined by screwing the screw 45 into the opening 53.

[0040] For this purpose, it is possible, firstly, to achieve a non-uniform rotational speed of the rotary tool effector 13 (visualized by the curve 58 which deviates from a sine curve in Fig. 20) compared to the constant-speed rotation of the drive spur gear 44 (visualized by the sine curve 59 in Fig. 20) to accept. On the other hand, the position of the longitudinal center axis 15 of the coupling body 10 in relation to the longitudinal center axis 8 of the coupling body receptacle 4 can be detected by means of the sensor 48 of the rotary head tool 2 and made available to the control unit. By means of the control unit, the rotary head tool 2 and / or the robot are then controlled in such a way that the drive cylinder 3 is spatially adjusted so that the longitudinal center axes 8, 15 coincide again. This is in Fig. 20 is indicated by the dotted lines 60. Alternatively, the rotary head tool 2 is controlled by the control unit when a deviation of the longitudinal center axes 8, 15 from each other is detected, such that the drive speed of the drive unit 43 is controlled such that a rotational speed profile of the drive cylinder 3 causes the coupling body 10 to rotate about its longitudinal center axis 15 at a constant rotational speed. This can also be done in addition to readjusting the drive cylinder 3.

[0041] In Fig. 18 to Fig. Figure 22 shows that the screw 45 has an (optional) alignment cone 62, by means of which the components 54, 55 are aligned with each other when the screw 45 is screwed into the opening 53 (see Fig. 21), by the alignment cone 62 sliding off an edge of a circular through-opening 63 of the body 55. The opposite through-opening 64 of the body 55 is designed as an elongated hole.

[0042] Fig. Figure 22 shows the car body 55 and the workpiece or strut mount 54 with the screws 45 fully screwed in. The components 54 and 55 are aligned as intended. This method is equally suitable for any machining operation in which the effector point 56 is used to approach a point on a workpiece surface and then penetrate the workpiece 54 translationally, i.e., in a straight feed direction, such as for countersinking, thread cutting, drilling, etc.

[0043] The invention is based on the following considerations: for example, for the automated screwdriving process to implement the "threading and thread finding" operation within a defined tolerance range, a lightweight socket can be mounted in the screwdriver housing with a low restoring force, floating almost frictionlessly and without inertial forces towards the center of the screwdriver housing. Torque is transmitted via a horizontal drive pin in the cup-shaped hollow bevel gear to two vertical drive pins in the socket. In the case of a center-centered socket in the screwdriver housing, the torque is transmitted symmetrically by both vertical drive pins. In the case of an off-center socket (tolerance compensation) in the screwdriver housing, the torque is transmitted off-center, alternating between only one of the vertical drive pins and half the rotation angle (180°) of the horizontal drive bar.For a measurement-control-based and self-learning optimization process, the screwdriver head can be equipped with sensors to monitor the X / Y position of the floating socket. These sensors transmit the differential measurements as correction values ​​to the robot control program at the start of the tightening process (once the screw has correctly engaged the first thread). A screw, optionally with a centering tip, is inserted into the screw socket by the robot screwdriver. Once the first thread is correctly engaged, the mechanical position tolerance compensation is enforced via the floating socket as the screw thread is tightened into the socket. Four of the six spatial degrees of freedom must be reliably compensated: primarily the two translational inaccuracies along the X and Y axes, and secondarily the two rotational degrees of freedom for tilting along the X and Y axes.The rotational degree of freedom around the Z-axis (screw axis) remains unobstructed for the screwing process, and the translational degree of freedom along the Z-axis remains unobstructed for the linear insertion of the fastening screw. With steady-state production and process tolerances in stationary manufacturing, a scatter field for the expected X / Y position of the screw bushing to be engaged quickly develops. The new target coordinates of the TCP (tool center point) for the robot axes used for thread finding can then be recalculated for each subsequent screwing operation via feedback to the robot control program. Alternatively or additionally, an AI program can self-learningly determine the optimal approach position from the scatter field of differential values, torque and speed data, as well as from problematic and incorrectly identified screw connections over a defined number of screwing operations.This programming is then maintained as a fixed setting over many process cycles until automatic correction loops are required again as a result of ongoing background process monitoring. The most important process condition, and one easily achievable through AI programming, is: Measured value X = Measured value Y = Setpoint for corrective adjustment of the robot axes.

[0044] In a self-learning screwdriving process, the robot, equipped with a screwdriver and a magnetically held screw with a centering tip, moves to the programmed target screw coordinates. The threaded screw with centering tip and the screwing motion mechanically compensate for tolerances via the floating socket during insertion, enabling further screw tightening. Distance sensors in the screwdriver head housing determine the positional deviation of the floating socket relative to the target center position in the housing in the X and Y axes. Alternatively, the rotational speed of the output relative to the input shaft can be evaluated.The difference between the measured actual coordinates of the floating socket in the ring gear and the target centered position is immediately fed back to the robot controller as correction values ​​during the tightening process. This ensures that the tightening process is completed with consistent torque and speed by correcting the robot axes and thus aligning the floating socket centrally in the screwdriver housing. Alternatively or additionally, the screwdriver output speed (socket speed) can be adjusted in real time and kept constant across the entire rotation angle by evaluating the measured values ​​(input and output speeds and / or the coordinates of the off-center socket). In this case, the robot axes can remain in their originally set coordinates until the tightening process is complete.

[0045] Mechanically, the screwdriver head is particularly simple in design and, compared to standard screwdrivers, is only made with a larger diameter to accommodate the required tolerance range. It can also be optionally equipped with two orthogonally arranged distance sensors and / or speed sensors for additional measurement and control technology. The floating socket is either a two-piece design with a press-fit connection via two drive pins, or a single-piece milled or cast component. Within the screwdriver's hollow bevel gear, the vertical drive pins of the socket are engaged by a horizontal drive pin for torque transmission and held in place by the lower part of the socket within the bevel gear. This results in the usual torque transmission when the socket is centered in the housing head.With an eccentrically mounted socket in tolerance compensation, a pulsating sinusoidal output is generated at a constant sinusoidal input speed. This output is achieved via the unilateral lever arm, which changes cyclically over half the rotation angle. The difference in length corresponds to the respective eccentricity of the screw movement relative to the target screw axis. It is conceivable to replace the two distance sensors with four spring-loaded force sensors (strain gauges or piezoelectric technology, etc.) that hold the socket in the screwdriver head center even with a small restoring force. Deviations would be detected immediately, similar to human perception, and used by the measurement and control system for screw axis correction (readjusting the TCP) or speed correction (for a constant sinusoidal output speed).The screwdriver head with its automatic misalignment compensation can also be used for automatic deburring of punched holes and bores, as well as for automatic tapping. A chuck can be provided as a design alternative to a socket holder or coupling, allowing deburring tools, countersinks, taps, or similar items to be mounted. This enables automated production processes while compensating for misalignment.

[0046] The screwdriver described herein, with a floating socket for tolerance compensation during thread finding in automated screwdriving processes, has a particularly simple design, and its wear parts can be replaced quickly and easily. The screw head housing size is only larger than that of a comparable screwdriver without tolerance compensation by the value of the desired tolerance range. The masses that would hinder tolerance compensation are minimized as much as possible.

[0047] In the case of a floating socket, tolerance compensation during screw threading requires overcoming only its inertia (including the screw) and its bearing friction within the housing. The positioning compensation process during thread engagement is supported by the unilateral force application point of the floating socket in the hollow bevel gear, which changes cyclically over half a rotational angle during off-center screw movement relative to the screw bushing axis. Alternatively, the drive speed is adjusted via the rotation angle using real-time monitoring of the rotational speed or socket position, resulting in a sinusoidal output speed of the socket even with off-center drive. The screwdriver can achieve tolerance compensation in all automated screwdriving processes, even without measurement and control technology, particularly when the off-center variation of the screw connection is within a small tolerance range.The slightly pulsating output torque and the resulting slightly increased tolerance range of the tightening torque can then be compensated for by a slightly higher specified tightening torque. For large tolerance ranges in the joining area of ​​the components to be screwed together, the screwdriver can be equipped with sensors and measurement and control technology, as described. This enables a self-learning and self-optimizing screwdriving process in which the determined screw head internal socket coordinates, speed fluctuations, or restoring forces act as feedback to the control program of the robot axes and / or the speed control of the screwdriver motor. Reference symbol list 1 rotary head unit 2 Rotary head tool 3 drive cylinders 4 Coupling body mount 5 Inner perimeter wall 6 Base area 7 Drive element 8 Longitudinal center axis of the coupling body holder 9 carriers 10 coupling bodies 11 Coupling body disk 12 coupling body disk 13 Rotary tool effector 14 drive bodies 15 Longitudinal center axis of the coupling body 16 outer radius 17 Tolerance field radius 18 Tolerance field 19 inner radius 20 route 21 Longitudinal center axis of the drive body 22 Outer edge point 23 Centering device 24 Spring element mount 25 spring element 26 Centering element 27 Centering element mount 28 Base circle radius 29 Leaf spring arrangement 30 leaf spring 31 kink 32 bend 33 Point of symmetry 34 bolts 35 round tub-shaped portion 36 slotted hole 37 Base 38 Drive unit 39 Spur gear ring 40 clamping pins 41 chuck 42 chucks 43 Drive unit 44 Drive spur gear 45 screw 46 Hexagon head 47 Holding magnet 48 Sensors 49 Distance sensor 50 Distance sensor 51 cases 52 deviation 53 Opening 54 workpiece 55 Body 56 effector point 57 Longitudinal axis of the opening 58 Curve 59 Curve 60 dotted line 61 dotted line 62 alignment cones 63 circular passage openings 64 slotted hole 65 Peak Position A B position C position D position E position F position

Claims

[1] Rotary head unit (1) for a rotary head tool (2), wherein the rotary head unit (1) comprises: - comprising a drive cylinder (3): - a hollow-circle cylindrical coupling body receptacle (4), - a drive element (7) arranged in a rotationally fixed manner with respect to the coupling body receptacle (4), which extends from an inner circumferential wall (5) of the coupling body receptacle (4) at least to a longitudinal central axis (8) of the coupling body receptacle (4), - a circular cylindrical coupling body (10) arranged in the coupling body receptacle (4), which is movably mounted along a base surface (6) of the coupling body receptacle (4) and has: - an outer radius (16) which is smaller than an inner radius (19) of the coupling body receptacle (4) by a specified tolerance field radius (17), - a first coupling body disk (11) and a second coupling body disk (12), between which the drive element (7) is arranged, wherein the second coupling body disk (12) is rotationally fixed to or connectable with a rotary tool effector (13), - a driver body (14) which extends parallel to a longitudinal center axis (15) of the coupling body (10), wherein the coupling disks (11, 12) are connected to each other at their edges in a rotationally fixed manner by means of the driver body (14). [2] Rotary head unit (1) according to claim 1, characterized by , that a radius-parallel segment (20) intersecting the longitudinal center axis (15) of the coupling body (10), over which a longitudinal center axis (21) of the drive body (14) and an outer edge point (22) of the coupling body (10) are spaced apart, is 1.3 times the inner radius (19) of the coupling body receptacle (4) or more. [3] Rotary head unit (1) according to claim 1 or 2, characterized bya centering device (23) which, in its relaxed state, holds the coupling body (10) centrally in the coupling body receptacle (4) and, in its tensioned state, drives the coupling body (10) into the center of the coupling body receptacle (4), wherein the centering device (23) comprises: - a spring element receptacle (24) formed in / on the drive cylinder (3) and in which a spring element (25) is seated, which clamps a centering element (26) parallel to the longitudinal center axis (8) of the coupling body receptacle (4) in the direction of the coupling body (10), which has a straight-conical centering element receptacle (27) whose base circle radius (28) is larger than the tolerance field radius (17), and / or - a leaf spring assembly (29) whose leaf springs (30) are arranged in the coupling body receptacle (4) and are fixed to the coupling body (10) or to the inner circumferential wall (5) of the coupling body receptacle (4). [4] Rotary head unit (1) according to any one of the preceding claims, characterized by , that the driver element (7) is designed as an elongated carrier (9) which extends completely or only to the longitudinal center axis (8) of the coupling body receptacle (4) through the coupling body receptacle (4). [5] Rotary head unit (1) according to claim 4, characterized by , that if the support (9) completely traverses the coupling body receptacle (4), a longitudinal section figure of the support (9) is point-symmetric with respect to a point of symmetry (33) which is formed by an intersection point at which the longitudinal center axis (8) of the coupling body receptacle (4) perpendicularly pierces the longitudinal section surface. [6] Rotary head unit (1) according to claim 4 or 5, characterized by , that the support (9) along its longitudinal extension direction - has a kink (31) and / or a bend (32) or - is completely straight. [7] Rotary head unit (1) according to any one of claims 4 to 6, characterized by , that the support (9) has a rectangular cross-sectional area or a circular cross-sectional area. [8] Rotary head unit (1) according to any one of the preceding claims, characterized by , that the coupling disks (11, 12) and the drive body (14) are materially bonded to each other, in particular formed in one piece together. [9] Rotary head unit (1) according to any one of claims 1 to 3, characterized by, that the drive element (7) is designed as an elongated hole (36) extending from the inner circumferential wall (5) of the coupling body receptacle (4) to the longitudinal center axis (8) of the coupling body receptacle (4) and completely penetrating a base (37) of the drive cylinder (3) having the base surface (6) of the coupling body receptacle (4), wherein the coupling body disks (11, 12) are spaced apart from each other along the longitudinal center axis (8) of the coupling body receptacle (4) via the base (37), and the drive body (14) extends through the elongated hole (36). [10] Rotary head unit (1) according to one of claims 1 to 7 or 9, characterized by , that the drive body (14) connecting the coupling body discs (11, 12) is designed as a bolt (34) manufactured separately from one or both of the coupling body discs (11, 12). [11] Rotary head unit (1) according to one of the preceding claims characterized bya drive device (48) connected to the drive cylinder (3) in a rotationally fixed manner, which - a spur gear ring (39), in particular in the form of a bevel gear ring, and / or - has a clamping pin (40). [12] Rotary head tool (2) with a rotary head unit (1) designed according to one of the preceding claims, the drive cylinder (3) of which and a drive unit (43) of the rotary head tool (2) are connected to each other in a rotationally fixed manner. [13] Rotary head tool (2) according to claim 12, characterized by - an electronic control unit and - a sensor system (48) configured to detect and provide to the control unit the position of the longitudinal center axis (15) of the coupling body (10) in relation to an effector point (56) of the rotary tool effector (13) which is non-rotatably connected to the second coupling body disk (12), wherein the control device is configured to detect a deviation of the longitudinal center axes (8, 15) from each other. - to spatially adjust the drive cylinder (3) so that the effector point (56) is moved to the longitudinal center axis (15), and / or - to control the drive speed of the drive unit (43) such that a rotational speed profile of the drive cylinder (3) causes the coupling body (10) to rotate about its longitudinal central axis (15) at a constant rotational speed. [14] Method in which a machining operation is carried out on an opening (53) of a workpiece (54) using the rotary head tool (2) designed according to claim 12 or 13, wherein - the effector point (56) is brought to a predetermined target coordinate such that a longitudinal center axis (57) of the opening (53) intersects a tolerance field (18) which has the tolerance field radius (17), - the rotary tool (2) is then moved in the feed direction (z), whereby a tip of the rotary tool effector (13) or a tip of a semi-finished product (45) coupled to the rotary tool effector (13) slides off an edge of the opening (53), thereby deflecting the coupling body (10) from the center of the coupling body receptacle (4) so ​​that the effector point (56) falls onto the longitudinal center axis (57) of the opening (53), - the drive cylinder (3) is driven by means of the drive unit (43). [15] Method according to claim 14, characterized by , that - by means of the sensor system (48) of the rotary tool (2) designed according to claim 13, a position of the longitudinal center axis (15) of the coupling body (10) in relation to the effector point (56) is detected and provided to the control unit, - the rotary head tool (2) is controlled by the control unit in such a way that, if the longitudinal center axis (15) of the coupling body (10) and the effector point (56) deviate from each other, - the drive cylinder (3) is spatially adjusted so that the effector point (56) is moved to the longitudinal center axis (15) of the coupling body (10), and / or - the drive speed of the drive unit (43) is controlled such that a rotational speed profile of the drive cylinder (3) causes the coupling body (10) to rotate about its longitudinal center axis (15) at a constant rotational speed.

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