System for inserting a penetrating element, and method for operating a system for inserting a penetrating element
The system addresses the issue of 'robot pushing' by employing a compensating unit with translational movement to reduce shear and bending forces, ensuring reliable insertion of high-strength screws and other elements into components.
Patent Information
- Application Number
- PCT/EP2025/069627
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-11
- Filing Date
- 2025-07-09
- Publication Date
- 2026-01-15
AI Technical Summary
High-strength screws, such as M4 or M4.5 screws, are frequently damaged during installation due to bending and shear forces caused by 'robot pushing', where the robot arm yields, leading to undesired tilting and misalignment of the screw relative to the component surface.
A system and method that utilize a compensating unit with translational movement to counteract 'robot pushing' effects, comprising an insertion unit with a rotary drive, linear drive, and a compensating unit with coupled elements allowing translational movement relative to each other, mitigating deflection and position changes of the insertion unit.
The system effectively reduces shear and bending forces on the penetration element by at least 40%, preventing damage and ensuring reliable insertion of high-strength screws and other elements like domes or drill bits into components.
Smart Images
Figure EP2025069627_15012026_PF_FP_ABST
Abstract
Description
[0001] System for introducing an ingress element and method for operating a system for introducing an ingress element
[0002] The invention relates to a system for introducing an indenter, in particular a screw, a dome or a drill bit, into a component.
[0003] For example, the invention relates to a system for placing a connecting element, in particular a screw or a dome, into a component.
[0004] The invention also relates to a method for operating a system for introducing an indenter, in particular a screw, a dome or a drill bit, into a component.
[0005] For example, the invention relates to a method for operating a system for placing a connecting element, in particular a screw or a dome, into a component.
[0006] A trend in the field of flow-drilling screws is the increasing use of high-strength M4 or M4.5 screws instead of the previously common M5 screws. Among other advantages, M4 or M4.5 screws are lighter, thus enabling weight savings.
[0007] However, it has been found that high-strength screws are more frequently damaged during installation than the established M5 screws. The applicant was able to analyze and determine that the damage to the high-strength screws is caused by bending and shear forces acting on the screws, with these bending and shear forces being generated by so-called "robot pushing".
[0008] "Robot slippage" refers to the yielding of a robot arm holding the screwing device during the screwing process. This yielding of the robot arm causes the screwing device to pivot, resulting in an undesired tilting of the screw relative to the component surface into which it is being screwed.
[0009] "Robot pushing" can also occur, for example, when inserting plastic domes into sandwich structures or during flow drilling. In these cases, plastic domes may be inserted at an angle into the sandwich structure, or irregular holes may be created during flow drilling.
[0010] EP 4 052 868 A1 discloses a solution for preventing screw misalignment caused by "robot pushing". EP 4 052 868 A1 teaches that the misalignment is compensated for by a pivoting movement of parts of the screw unit.
[0011] It is an object of the present invention to provide an alternative system for introducing an intruder element by means of which ‘robot pushing’ can be compensated in a structurally simpler and therefore more cost-effective way.
[0012] Furthermore, it is an object of the present invention to provide a method for operating a system for introducing an intruder element, in particular a screw, a dome or a drill bit, into a component, by means of which the ‘robot pushing’ can be compensated in a simpler and therefore cost-effective manner.
[0013] The problem is solved by a system for introducing an intruder having the features of claim 1. The problem is further solved by a method according to the independent method claim. Preferred embodiments are described in the dependent claims, the description, and the drawings.
[0014] The system for inserting an penetrant, for example a screw, a dome or a drill bit, into a component comprises an insertion unit with
[0015] - a case,
[0016] - a tool holder for holding a tool,
[0017] - a rotary drive to set the tool holder into a rotary motion,
[0018] - a linear drive to move the tool holder into a feed motion and
[0019] - an interface to attach the insertion unit - directly or indirectly - to an articulated robot arm, so that the articulated robot arm carries the insertion unit.
[0020] The system further comprises a compensating unit with a first element, a second element, and a bearing, wherein the first and second elements are coupled to each other via the bearing in such a way that the first and second elements are translationally movable relative to each other. The first and second elements are mounted in such a way that a deflection of a robot axis of the articulated robot due to pressing forces and a resulting change in the position of the insertion unit can be at least partially compensated. Such a bearing can be designed in many different ways. Several such bearings are described by way of example in the present application.
[0021] The invention is based on the general idea that, contrary to the teaching of EP 4 052 868 A1, not only a pivoting of the screw unit is suitable for compensating for "robot pushing". Instead, the applicant has surprisingly discovered that a translational compensating movement of the insertion unit, for example the screw unit, also makes it possible to compensate for the effect of "robot pushing" in such a way that an insertion process, for example a screwing process, can be carried out reliably.
[0022] Advantageous embodiments of the invention can be found in the dependent claims, the description and the drawings.
[0023] According to one embodiment, the first element is coupled or can be coupled to a housing of the insertion unit. Preferably, the first element is fixedly coupled or can be coupled to the housing of the insertion unit, i.e., not movable relative to each other. The first element can also be part of the housing. The second element is preferably designed to be coupled—directly or indirectly—to the articulated robot arm. In other words, the compensation unit is preferably arranged between the insertion unit and the articulated robot arm. This allows the compensation unit to be retrofitted into existing systems without significant design effort.
[0024] According to one embodiment, the second element is rigidly coupled to the articulated robot arm, meaning it is not movable relative to the first element. If the first element is rigidly coupled to the housing of the insertion unit and the second element is rigidly coupled to the articulated robot arm, the compensating movement of the compensating unit is generated solely by the compensating unit's bearing. This has the advantage of allowing a defined compensating movement to be generated in a simple manner.
[0025] Preferably, the compensating movement is a parallel displacement. Alternatively, the compensating movement can be a superimposed movement consisting of a parallel displacement and a rotational movement. The compensating movement is preferably effected by exactly one type of bearing, and thus, for example, not by a combination of a bearing for generating a tilting movement of the insertion unit and a separate bearing for generating a translational movement of the insertion unit.
[0026] According to one embodiment, the rotary drive's axis of rotation is arranged parallel, and in particular concentrically, to the axis of rotation of the tool holder. Alternatively or additionally, the linear drive's direction of movement can be aligned parallel to the axis of rotation of the tool holder. Preferably, the rotary drive's axis of rotation is always parallel, and in particular concentrically, to the axis of rotation of the tool holder during operation. Alternatively or additionally, the linear drive's direction of movement can always be aligned parallel to the axis of rotation of the tool holder during operation. This optimizes the force transmission of the clamping force from the system to the component.
[0027] According to one embodiment, the compensation unit is designed as a separate compensation module that can be mounted between the insertion unit and the articulated robot arm. According to an alternative embodiment, the compensation unit can also be integrated into the articulated robot arm or the insertion unit. According to one embodiment, the bearing allows, during operation, a translational movement of the first element relative to the second element in a direction perpendicular to an axis of rotation of the tool holder. Preferably, the bearing allows, during operation, a translational movement of the first element relative to the second element exclusively in a direction perpendicular to the axis of rotation of the tool holder. In other words, the compensation movement can be achieved by a translational movement of the tool holder and, if applicable, other parts of the insertion unit in a direction perpendicular to the axis of rotation of the tool holder.Such a system has the advantage of being particularly easy to implement in terms of design.
[0028] According to one embodiment, the bearing allows, during operation, a translational movement of the first element relative to the second element, with one component in a direction perpendicular to the axis of rotation of the tool holder and one component parallel to the axis of rotation of the tool holder. Preferably, the translational movement occurs along a straight line extending obliquely to the axis of rotation of the tool holder. Preferably, the bearing allows, during operation, a translational movement of the first element relative to the second element exclusively in a direction oblique to the axis of rotation of the tool holder. For this purpose, the bearing can, for example, have a guide surface extending obliquely to the axis of rotation of the tool holder, thus allowing a guided movement of the first element relative to the second element obliquely to the axis of rotation of the tool holder.A compensating movement at an angle to the axis of rotation of the tool holder has the advantage that "robot pushing" can be compensated for particularly well.
[0029] According to one embodiment, the first element and the second element are coupled to each other via the bearing in such a way that the first element and the second element are only movable translationally relative to each other. In other words, the first element and the second element can be mounted relative to each other via the bearing in such a way that the relative movement between the first element and the second element contains no rotational component, i.e., no pivoting movement.
[0030] To enable the system to automatically return from a compensating position to a home position after the penetration process, the system preferably includes a return element. The first element is preferably movable relative to the second element from a home position to a compensating position against a return force of the return element. The return element preferably acts between the first and second elements and serves to move the first element relative to the second element from a compensating position back to its home position.
[0031] According to one embodiment, the return element is located between the first and second elements. This allows for a particularly simple system design. The return element is preferably mechanically coupled to the first and second elements.
[0032] To store the kinetic energy of the movement from the home position to the balanced position particularly efficiently, the return element is advantageously designed as a spring element. The spring element can, for example, be a coil spring, especially a coil compression spring. The spring element can be made of metal, especially spring steel. Alternatively, the spring element can be a gas spring or an elastomer compression spring. Other types of spring elements are also conceivable.
[0033] To adapt the compensating unit and thus the system to different processes, such as screwing flow-drilling screws into various materials, setting domes of different sizes, or drilling holes of different diameters, the restoring force of the restoring element can be adjustable. Alternatively or additionally, the restoring force profile of the restoring element can be adjustable. For this purpose, the system can include a preloading device to preload the restoring element. The preloading device can include an adjustment element to set the magnitude of the preload applied to the restoring element.
[0034] The compensation unit preferably comprises an end stop with a first stop surface and a second stop surface. The first stop surface and the second stop surface can, for example, serve to define a home position, i.e., a relative position between the first element and the second element corresponding to the home position. The home position is considered to be a position in which the system is attached to the robot arm, but no forces beyond gravity act on the system, i.e., the system is unloaded. The first stop surface and the second stop surface preferably serve to limit the compensation movement of the compensation unit on one side.
[0035] The compensating unit may alternatively or additionally include an end stop that defines a maximum compensating position, i.e., a maximum change in the relative position between the first element and the second element starting from the initial position. The end stops may be adjustable with respect to their position.
[0036] According to one embodiment, the first element and / or the second element can be designed as a flat plate. This allows the first element and / or the second element to be manufactured easily and positioned with precision. The first element and / or the second element can include at least one opening, and in particular several openings, for fixed coupling with another part of the system, for example, the housing of the insertion unit or a part of the articulated robot arm.
[0037] Preferably, the insertion unit is designed as a setting unit for inserting elements, in particular connecting elements. For this purpose, the system can include a feeding unit to automatically feed an element, in particular a connecting element, e.g., a screw or a boss, to the insertion unit. The feeding unit can, for example, define a path along which the element to be inserted is fed to the insertion unit. The path can be defined by a hose and / or a guide rail. Alternatively, the insertion unit can be designed for drilling holes, in particular for flow drilling.
[0038] The invention further relates to the use of a system described above or below for processing screws, in particular flow-drilling screws. In particular, the system described above or below is especially well suited for processing high-strength flow-drilling screws, for example, high-strength M4 screws or M4.5 screws. Additionally or alternatively, the invention relates to the use of a system described above or below for processing domes, in particular plastic domes, for example, in sandwich structures. Alternatively or additionally, the invention relates to the use of a system described above or below for drilling holes, in particular for flow drilling. Generally, the invention relates to the use of a system described above or below for any process in which the component is not pre-drilled at a point to be processed, e.g.,Flow drilling, friction stir welding and the placement of plastic domes.
[0039] The invention further relates to a method for operating a system for inserting a penetration element, in particular a screw, a dome, or a drill bit, into a component. Preferably, the method can be used to operate a screw system for processing screws, in particular flow-drilling screws. Additionally or alternatively, the method can be used for processing domes, in particular plastic domes, for example in sandwich structures. Again, alternatively or additionally, the method can be used for drilling holes, in particular flow drilling. Generally, the method can be used for any process in which the component is not pre-drilled at the point to be processed, e.g., flow-drilling screws, friction stir welding, and the insertion of plastic domes.
[0040] The process includes the following steps:
[0041] - Providing an insertion unit held via an interface on an articulated robot arm, wherein the insertion unit comprises a housing, a tool holder for receiving a tool, a rotary drive to set the tool holder in a rotary motion, and a linear drive to set the tool holder in a feed motion, wherein the system comprises at least one compensating unit with a first element, a second element, and a bearing, wherein the first element and the second element are coupled to each other via the bearing in such a way that the first element and the second element are translationally movable relative to each other, and
[0042] - Insertion of the penetration element into the component using the system, while the compensation unit at least partially compensates for a deflection of a robot axis of the articulated robot due to contact forces and a resulting change in position of the insertion unit by means of a translational movement between the first element and the second element.
[0043] According to one embodiment of the method, the system has one of the aforementioned or subsequent features. In particular, the insertion unit and / or the compensation unit may have at least one of the aforementioned or subsequent features.
[0044] According to one embodiment, the contact forces are axial forces acting along a rotational axis of the insertion unit. The axial forces acting on the insertion unit preferably generate the translational movement between the first element and the second element. The axial force preferably causes a constrained relative movement between the first element and the second element.
[0045] The invention is described below with reference to purely exemplary embodiments and the accompanying drawings. These show:
[0046] Fig. 1 A a sketch of an unloaded system for introducing an intruder;
[0047] Fig. 1 B shows a sketch of a system subjected to bending stress for the insertion of a penetration element;
[0048] Fig. 1 C a sketch of a system compensating for the shear forces caused by the bending load for the insertion of a penetrating element;
[0049] Fig. 2 shows a system for introducing an intruder element with a compensation module according to a first variant;
[0050] Fig. 3A shows a side view of the compensation module according to the first variant in a basic position;
[0051] Fig. 3B shows a side view of the compensation module according to the first variant in a compensation position;
[0052] Fig. 3C shows a side sectional view of the compensation module according to the first variant in the basic position;
[0053] Fig. 3D shows a side sectional view of the compensation module according to the first variant in the compensation position; Fig. 4 shows a top view of the compensation module according to the first variant;
[0054] Fig. 5 shows a system for introducing an intruder element with a compensation module according to a second variant;
[0055] Fig. 6A shows a side view of the compensation module according to the second variant in a basic position;
[0056] Fig. 6B shows a side view of the compensation module according to the second variant in a compensation position;
[0057] Fig. 6C shows a side sectional view of the compensation module according to the second variant in the basic position;
[0058] Fig. 6D shows a side sectional view of the compensation module according to the second variant in the compensation position;
[0059] Fig. 6E shows a side view of the compensating module according to the second variant in the compensating position, in which the slot-forming plates are hidden to show the interior of the compensating module;
[0060] Fig. 7A shows a top view of the compensation module according to the second variant in a basic position;
[0061] Fig. 7B shows a top view of the compensating module according to the second variant in a compensating position in which a lower slot-forming plate is hidden;
[0062] Fig. 8 shows a system for introducing an intruder element with a compensation module according to a third variant;
[0063] Fig. 9A shows a side view of the compensation module according to the third variant in a basic position;
[0064] Fig. 9B shows a side view of the compensation module according to the third variant in a compensation position;
[0065] Fig. 9C shows a side view, partially cut away, of the compensation module according to the third variant in the basic position;
[0066] Fig. 9D shows a side view, partially cut away, of the compensation module according to the third variant in the compensation position; Fig. 10 shows an enlarged side view, partially cut away, of the compensation module according to the third variant in the compensation position of Fig. 9D;
[0067] Fig. 1 shows a top view of the compensation module according to the third variant in the basic position; and
[0068] Fig. 12 shows a perspective view of the compensation module according to the third variant.
[0069] Figures 1A to 1C show a sketch of a system 10 for inserting an insertion element 12, for example a screw, a dome or a drill bit, into a component 14. The system 10 comprises an insertion unit 18, for example a screw unit, which is attached to a free end of a robot arm 15 of an articulated robot 16, i.e. an industrial robot, in order to be moved by the articulated robot 16 to the respective place of use.
[0070] Figure 1A shows the system 10 in a home position. In this home position, the system 10 exerts no force on the component 14. Conversely, no corresponding reaction force, i.e., counterforce, acts on the system 10. The articulated robot arm 16 is thus only subjected to the weight of the insertion unit 18, so that a central axis of the insertion element 12 is oriented essentially perpendicular to a component surface 14a.
[0071] Figure 1B shows the system 10 in a working position. In this position, the indenter 12 rests on the component 14, thereby transmitting an axial force from the system 10 to the component 14 via the indenter 12. Conversely, a reaction force acts on the system 10, causing the articulated robot arm 16 to yield, i.e., deform, as illustrated by the curved representation of the robot arm 15. This results in the central axis of the indenter 12 aligning obliquely with the component surface 14a. Consequently, if the component 14 did not prevent the indenter 12 from moving, the end 12a of the indenter 12 facing the component 14 would move away from the robot arm 15 on the component 14, to the right in this image.The inclined orientation of the connecting element 12 causes unwanted shear and bending forces to act on the penetrating element 12, which can damage the penetrating element 12. The described effect is referred to as "robot pushing".
[0072] Figure 1C schematically shows a solution to this problem. The system 10 performs a compensatory movement, so that the shear and / or bending forces on the penetration element 12 are significantly reduced, for example by at least 40%. Consequently, lower shear and bending forces act on the penetration element 12, thus preventing damage to the penetration element 12. In other words, the compensatory movement of the system at least partially compensates for a deflection of a robot axis of the articulated robot due to pressing forces and the resulting change in position of the insertion unit 18.
[0073] Figures 2 to 4 show a first variant of a system 10 for inserting an indenter 12. For example, the system 10 could be a screw system for processing flow-drilling screws. The system comprises an insertion unit 18, which serves to insert the indenter 12, e.g., a screw, a dome, or a drill bit, into a component.
[0074] The insertion unit 18 comprises a housing 20, which in this case is designed to be open, so that some of the components of the insertion unit 18 are visible and accessible from the outside. The insertion unit 18 also comprises a tool holder 22, which serves to be coupled with a tool 24, for example, a bit. If the insertion element is designed, for example, as a drill bit, the tool and the insertion element can be the same part, and the tool holder can be designed as a drill chuck. The insertion unit 18 also comprises a rotary drive 26. The rotary drive 26 is advantageously designed as an electric motor. In this case, the rotary drive 26 is designed concentrically with the tool holder 22. The rotary drive 26 serves to set the tool holder 22 into a rotary motion during operation.
[0075] The insertion unit 18 also includes a linear drive 28. The linear drive 28 can be designed, for example, as a pneumatic drive, e.g., as a pneumatic cylinder, or as an electric drive. The linear drive 28 serves to move the tool holder 22 forward during operation.
[0076] The insertion unit 18 has an interface 30 with coupling means 31, e.g., screws, to couple the insertion unit 18 directly or indirectly to the free end of the robot arm 15. In other words, the insertion unit 18 is designed to be attached to the robot arm 15 in such a way that the insertion unit 18 is supported by the robot arm 15 and can be moved by a movement of the robot arm 15.
[0077] System 10 further comprises a compensation unit 32 to at least partially compensate for the "robot pushing" effect described above with reference to Figures 1A to 1C. In this case, the compensation unit 32 is designed as a separate compensation module 32. The compensation module 32 is arranged between the insertion unit 18 and the free end of the robot arm 15.
[0078] Figures 3A to 3D and 4 show the compensation module 32 in detail according to the first variant. Figures 3A and 3C show the compensation module 32 in a basic position, while Figures 3B and 3D show it in a compensating position. The compensation module 32 comprises a first element 34 and a second element 36. The first element 34 is used to couple with the insertion unit 18. The second element 36 is used to couple with the free end of the robot arm 15. The first element 34 and the second element 36 are mounted to allow movement relative to each other, enabling a compensating movement to counteract robot slippage. For this purpose, a bearing 38 is provided, which, in the first variant, allows a superimposed translational and rotational movement of the first element 34 relative to the second element 36.
[0079] In this case, the bearing 38 comprises four arms 44, each rotatably mounted with the first element 34 and the second element 36. The first arms, shown as upper arms 44a in the drawings, and the second arms, shown as lower arms 44b in the drawings, are arranged at an angle to each other, i.e., the first arms 44a do not extend exactly parallel to the second arms 44b. This applies to the basic position (see Fig. 3A) as well as to the compensating position (see Fig. 3B).
[0080] The first arms 44a, in this case the two upper arms 44a, are longer than the second arms 44b, in this case the lower arms 44b. This positions the first element 34 relative to the second element 36 in such a way that, when moving from its home position to the balancing position, the first element 34 moves towards the second element 36, simultaneously laterally and upwards relative to the second element 36, and is also tilted relative to the second element 36. Thus, when the first element 34 moves from its home position to the balancing position, it performs a superimposed translational and rotational movement relative to the second element 36. Consequently, a translational offset and a pivoting of the insertion unit 18 due to "robot pushing" are compensated for. Alternatively, all four arms could be the same length.In this case, the bearing would not produce a tilting motion, i.e., a rotational motion, between the first element 34 and the second element 36, but a purely translational motion between the first element 34 and the second element 36.
[0081] The compensating module 32 also includes a return element 40. The return element 40 is functionally and spatially located between the first element 34 and the second element 36. In this case, the return element 40 is designed as a spring element 40, specifically as a helical compression spring. When the first element 34 moves from its home position to the compensating position relative to the second element 36 due to the reaction force acting on the insertion unit 18 and thus on the first element 34 during the insertion of the indenter 12, the kinetic energy of the first element 34 is converted into potential energy, thereby pre-tensioning the return element 40. As soon as the reaction force of the component 14 on the system 10 decreases, the energy stored in the return element 40 ensures that the first element 34, and thus also the insertion unit 18, is automatically moved back towards its home position.
[0082] To adapt the restoring force and / or the spring characteristic of the restoring element 40 to different applications, e.g., insertion units 18 of varying weights, the preload of the restoring element 40 can be adjusted. For this purpose, a preloading device 46 is provided in the present embodiment to adjust the preload of the restoring element 40. The preloading device 46 comprises an adjusting element 48 with a first threaded section, which engages with a second threaded section associated with the second element 36. By rotating the adjusting element 48 relative to the second element 36, the restoring element 40 can be tensioned or released, depending on the direction of rotation. The compensating module 32 also includes a first end stop 50 (see Fig. 3D), which defines the basic position of the compensating module 32.The end stop 50 comprises a first stop surface 52, which is assigned to the first element 34, and a second stop surface 54, which is assigned to the second element 36. In the home position, the return element 40 presses the first stop surface 52 against the second stop surface 54. The position of the first end stop 50, and thus the relative position of the first element 34 to the second element 36 in the home position, is adjustable. In this case, a screw forms the second stop surface 54, which is adjustably coupled to the second element 36.
[0083] The compensating module 32 also includes a second end stop 56, which limits the movement of the first element 34 relative to the second element 36 in the direction of the compensating position. This second end stop 56 primarily serves as overload protection and thus prevents overloading of the return element 40 if a surprisingly large reaction force acts on the insertion unit 18.
[0084] Fig. 4 shows a top view of the compensation module 32. Fig. 4 shows that the return element 40 is arranged essentially centrally between the two first arms 44a.
[0085] Figures 5 to 7B show a second variant of a system 10' for introducing an indenter 12 into a component 14. The second variant of the system 10' differs from the first variant only in the design of the compensating unit 32'.
[0086] The compensating unit 32' also serves to at least partially compensate for the "robot pushing" effect described above with reference to Figures 1A to 1C. In this case, the compensating unit 32' is also designed as a separate compensating module 32' and is arranged between the insertion unit 18 and the free end of the robot arm 15.
[0087] Figures 6A to 6E, 7A and 7B show the modulus of 32' according to the second variant in detail. Figures 6A and 6C show the modulus of 32' in a basic position, while figures 6B, 6D and 6E show it in a modified position.
[0088] Analogous to the first variant, the compensation module 32' comprises a first element 34' and a second element 36'. Accordingly, the first element 34' is coupled to the insertion unit 18, and the second element 36' is coupled to the free end of the robot arm 15. The first element 34' and the second element 36' are also mounted to allow movement relative to each other, enabling a compensatory movement to counteract robot slippage. However, in the second variant, a bearing 38' is provided for this purpose, which permits only translational movement between the first element 34' and the second element 36'. The bearing 38' includes linear guides 58' in the form of elongated slots and guide elements 60' movable along the linear guides 58', which in this case are exemplified as rollers. The linear guides 58' extend obliquely to a rotary axis 22a of the tool holder 22.More precisely, the linear guides 58' extend along a straight line which extends obliquely to the axis of rotation 22a of the tool holder 22 and obliquely to a perpendicular to the axis of rotation 22a of the tool holder 22.
[0089] In the usual position of the insertion unit 18 shown in Fig. 5 during an insertion process, the linear guides 58' extend obliquely from bottom to top, so that the first element 34' performs a movement which has a vertical and a horizontal component when the first element 34' moves relative to the second element 36' from the home position (see Fig. 6A) to the compensation position (see Fig. 6B).
[0090] The compensating module 32' also includes a return element 40' (see Fig. 6C). The return element 40' is functionally and spatially arranged between the first element 34' and the second element 36'. In this case, the return element 40' is also designed as a spring element, specifically as a helical compression spring. The main extension direction of the return element 40', in this case the central axis of the spring element, is aligned parallel to the linear guide 58', so that the return element 40' only has to absorb small bending forces during relative movement between the first element 34' and the second element 36'. When the first element 34' moves relative to the second element 36' from the home position to the compensating position, the kinetic energy of the first element 34' is converted into potential energy, thus pre-tensioning the return element 40'.As soon as the reaction force of component 14 on system 10 decreases, the energy stored in the return element 40' ensures that the first element 34' and thus also the insertion unit 18 is automatically moved back towards its home position.
[0091] To adapt the restoring force and / or the spring characteristic of the restoring element 40' to different applications, e.g., insertion units 18 of varying weights or different positions of the insertion unit 18 in space, the preload of the restoring element 40' can be adjusted. For this purpose, a preloading device 46' is also provided in the present embodiment to adjust the preload of the restoring element 40'. The preloading device 46' comprises an adjusting element 48' with a first threaded section 48a', which engages with a second threaded section associated with the second element 36'. By rotating the adjusting element 48' relative to the second element 36', the restoring element 40' can be tensioned or released, depending on the direction of rotation. The compensating module 32' also includes a first end stop 50' (see Fig. 6C), which defines the basic position of the compensating module 32'.The end stop 50' comprises a first stop surface 52', which is assigned to the first element 34', and a second stop surface 54', which is assigned to the second element 36'. In the home position, the return element 40' presses the first stop surface 52' against the second stop surface 54'. In the second variant, the position of the first stop surface 52' relative to the first element 34' is adjustable. This allows the relative position of the first element 34' to the second element 36' to be changed in the home position. In this case, a screw forms the first stop surface 54' and a sleeve forms the second stop surface 54'.
[0092] As with the first variant, the second variant of the compensating module 32' also includes a second end stop 56' (see Fig. 6E), which limits the movement of the first element 34' relative to the second element 36' in the direction of the compensating position. In this case, the end stop 56' has two corresponding stop surfaces, which are arranged perpendicular to the direction of movement of the first element 34'. This second end stop 56' primarily serves as overload protection and thus prevents overloading of the return element 40' if a surprisingly large reaction force acts on the insertion unit 18.
[0093] Fig. 7A shows a top view of the compensating module 32' in its home position, and Fig. 7B shows a top view of the compensating module 32' in its working position. In Fig. 7B, a plate 59 defining the linear guide 58' is hidden to better show the guide element 60 guided relative to the plate 59. A comparison of Figs. 7A and 7B shows, among other things, that the distance A between the first element 34' and the second element 36' in the home position is greater than the distance B between the first element 34' and the second element 36' in the compensating position. It can also be seen that the return element 40' is arranged essentially centrally between two plates 59 forming linear guides 58'.
[0094] Figures 8 to 12 show a third variant of a system 10" for introducing an intruder element 12. The system 10" differs from the previously described systems 10 and 10' by the design of the compensating module 32".
[0095] The compensating unit 32" also serves to at least partially compensate for the "robot pushing" effect described above with reference to Figures 1A to 1C. In this case, the compensating unit 32" is also designed as a separate compensating module 32" and is arranged between the insertion unit 18 and the free end of the robot arm 15.
[0096] Figures 9A to 9D, 10, 11, and 12 show the 32" compensatory modulus according to the third variant in detail. Figures 9A and 9C show the 32" compensatory modulus in a basic position, while figures 9C and 9D show it in a compensatory position.
[0097] Analogous to the first and second variants, the compensation module 32" comprises a first element 34" and a second element 36". Accordingly, the first element 34" is designed to be coupled to the insertion unit 18, and the second element 36" is designed to be coupled to the free end of the robot arm 15. The first element 34" and the second element 36" are also mounted to allow movement relative to each other in order to perform a compensating movement to counteract robot slippage. For this purpose, however, the third variant provides a bearing 38" which permits only translational movement between the first element 34" and the second element 36" perpendicular to the axis of rotation of the tool holder 22 and / or perpendicular to the axis of rotation of the rotary drive 26. The bearing 38" comprises linear guides 58" in the form of sleeves and guide elements 60" movable along the linear guides 58" (see Fig.9C), which in the present case are designed as rods sliding in the sleeves.
[0098] As can be seen by comparing Figures 9A and 9B, the first element 34" and the second element 36" are further apart in the home position (see Fig. 9A) than in the compensating position (see Fig. 9B). The first element 34" and the second element 36" thus move towards each other when the compensating module 32" is moved from the home position to a compensating position.
[0099] The compensating module 32" also includes a return element 40" (see Fig. 10). The return element 40" is functionally and spatially arranged between the first element 34" and the second element 36". In this case, the return element 40" is also designed as a spring element, specifically as a helical compression spring. The effective axis of the return element 40", in this case the central axis of the spring element, is aligned parallel to the possible direction of movement of the linear guide 58". This means that the return element 40" only has to absorb minimal bending forces during relative movement between the first element 34" and the second element 36". When the first element 34" moves relative to the second element 36" from its home position to the compensating position, the kinetic energy of the first element 34" is converted into potential energy, thus pre-tensioning the return element 40".As soon as the reaction force of component 14 on system 10 decreases, the energy stored in the return element 40" ensures that the first element 34', and thus also the insertion unit 18, is automatically moved back towards its initial position. In the third variant, unlike the first two variants, the preload of the return element 40" is not adjustable. Alternatively, it could be designed to be adjustable.
[0100] The compensating module 32" comprises a first end stop 50" (see Fig. 10), which defines the basic position of the compensating module 32". The end stop 50" comprises a first stop surface 52", which is assigned to the first element 34", and a second stop surface 54", which is assigned to the second element 36". In the basic position, the return element 40" presses the first stop surface 52" against the second stop surface 54". In the third variant, neither the position of the first stop surface 52" relative to the first element 34" nor the position of the second stop surface 54" relative to the second element 36" is adjustable. Alternatively, however, it would also be conceivable to design the position of the first stop surface 52" relative to the first element 34" and / or the position of the second stop surface 54" relative to the second element 36" to be adjustable.
[0101] As with the first and second variants, the third variant of the compensating module 32" also includes a second end stop 56" (see Fig. 10), which limits the movement of the first element 34" relative to the second element 36" in the direction of the compensating position. In the third variant, this second end stop 56" is formed by stop surfaces on the first element 34" and the second element 36". Here, too, the second end stop 56" primarily serves as overload protection and thus prevents overloading of the return element 40" when a surprisingly large reaction force acts on the insertion unit 18.
[0102] Fig. 11 shows a top view of the compensating module 32" in its initial position. As can be seen in Fig. 11, the compensating module 32" comprises four linear guides 58", two first linear guides 58a" (top in the figures) and two second linear guides 58b" (bottom in the figures). The compensating module 32" also includes two return elements 40". Each return element 40" is arranged centrally between a first linear guide 58a" and a second linear guide 58b".
[0103] Fig. 12 shows a perspective view of the compensation module 32". Fig. 12 shows, among other things, that the two first linear guides 58a" are spaced further apart than the two second linear guides 58b". Surprisingly, it has been found that even such a compensation unit 32' or 32", which only allows offset compensation at an angle or parallel to the component surface 14a, but does not allow any pivoting of the insertion unit 18, is sufficient to reliably insert, for example, high-strength M4 or M4.5 screws into a component and thus reliably compensate for robot movement.
[0104] Reference symbol list
[0105] 10 System
[0106] 12 Penetrating element
[0107] 12a End facing component
[0108] 14 Component
[0109] 14a Component surface
[0110] 15 robot arm
[0111] 16 articulated arm robots
[0112] 16a Robot axis
[0113] 18 insertion units
[0114] 20 cases
[0115] 22 Tool holder
[0116] 22a Rotary axis
[0117] 24 tools
[0118] 26 Rotary drive
[0119] 28 Linear actuator
[0120] 30 interface
[0121] 31 Coupling devices
[0122] 32 Compensation unit
[0123] 34 first element
[0124] 36 second element
[0125] 38 bearings
[0126] 40 Reset element
[0127] 42 Feed unit
[0128] 44 Arm
[0129] 44a first arm
[0130] 44b second arm
[0131] 46 Pre-tensioning device
[0132] 48 Adjustment element
[0133] 48a Thread section
[0134] 50 first end stop
[0135] 52 first stop surface
[0136] 54 second stop surface
[0137] 56 second end stop
[0138] 58 Linear guide
[0139] 59 plate
[0140] 60 guide element
Claims
Claims 1. System (10) for inserting an insertion element (12), in particular a screw, a dome or a drill bit, into a component (14), comprising an insertion unit (18) with a housing (20), a tool holder (22) for receiving a tool (24), a rotary drive (26) for rotating the tool holder (22), a linear drive (28) for moving the tool holder forward, and an interface (30) for attaching the insertion unit (18), directly or indirectly, to an articulated robot arm (16) so that the articulated robot arm (16) carries the insertion unit (18), characterized by a compensating unit (32) with a first element (34), a second element (36) and a bearing (38), wherein the first element (34) and the second element (36) are coupled to each other via the bearing (38) such that the first element (34) and the second element (36) are translationally movable relative to each other,so that a deflection of a robot axis (16a) of the articulated robot due to contact forces and a resulting change in position of the insertion unit (18) can be at least partially compensated.
2. System according to claim 1, characterized in that the first element (34) is coupled to the housing (20) of the insertion unit (18) or the first element (34) is part of the housing (20) and the second element (36) is couplingable to the articulated arm robot (16).
3. System according to claim 1 or 2, characterized in that the bearing (38") allows in operation a translational movement of the first element (34") relative to the second element (36") in a direction perpendicular to a rotation axis (22a) of the tool holder (22).
4. System according to at least one of claims 1 to 3, characterized in that the bearing (38') allows a translational movement of the first element (34') relative to the second element (36') during operation, wherein the movement comprises a component in a direction perpendicular to a rotation axis (22a) of the tool holder (22) and a component parallel to the rotation axis (22a) of the tool holder (22).
5. System according to at least one of the preceding claims, characterized in that the first element (34) and the second element (36) are coupled to each other via the bearing in such a way that the first element (34) and the second element (36) are movable to each other exclusively translationally.
6. System according to one of the preceding claims, characterized in that the system (10) comprises a restoring element (40), and that the first element (34) is movable relative to the second element (36) from a basic position to a compensating position against a restoring force of the restoring element (40).
7. System according to claim 6, characterized in that the return element (40) is arranged between the first element (34) and the second element (36) and / or that the return element (40) is mechanically coupled to the first element (34) and the second element (36).
8. System according to claim 6 or 7, characterized in that the return element (40) is designed as a spring element.
9. System according to at least one of claims 6 to 8, characterized in that the height of the restoring force of the restoring element (40) and / or the course of the restoring force of the restoring element (40) is adjustable.
10. System according to at least one of the preceding claims, characterized in that the first element (34) and / or the second element (36) is designed as a flat plate.
11. System according to at least one of the preceding claims, characterized in that the system (10) comprises a feed unit (42) to automatically feed the penetrating element (12), in particular a screw or a dome, to the insertion unit (18).
12. Use of a system (10) according to at least one of the preceding claims, for processing screws, in particular flow-drilling screws, for setting domes, in particular plastic domes, for drilling holes, in particular for flow drilling holes, and / or for friction stir welding.
13. Method for operating a system (10) for introducing an indenter (12), in particular a screw, a dome or a drill bit, into a component, in particular a screw system for processing flow-drilling screws, comprising the steps: Providing an insertion unit (18) held on an articulated robot arm (16) via an interface (30), wherein the insertion unit (18) comprises a housing (20), a tool holder (22) for receiving a tool (24), a rotary drive (26) to set the tool holder (22) into a rotary motion, and a linear drive (28) to set the tool holder (22) into a feed motion, characterized in that the system comprises at least one compensating unit (32) with a first element (34), a second element (36) and a bearing (38), wherein the first element (34) and the second element (36) are coupled to each other via the bearing (38) such that the first element (34) and the second element (36) are translationally movable relative to each other, and inserting the indenter element (12) into the component (14) by means of the system (10).while the compensation unit (32) at least partially compensates for a deflection of a robot axis of the articulated robot arm (16) as a result of pressing forces and a resulting change in position of the insertion unit (12) by means of a translational movement between the first element (34) and the second element (36).
14. Method according to claim 13, characterized in that the system (10), in particular the insertion unit (12) and / or the compensation unit (32), has at least one of the features of claims 1 to 12.