Gripping device for force-locking gripping or positioning of components, in particular grippers for gripping workpieces, and centering device

Abstract

The invention relates to a gripping device (1) for the non-positive gripping of components, in particular a gripping device (1) for gripping prismatic workpieces, wherein the gripping device (1) has elastic projecting elements (3, 3'), in which the gripping device (1) has a base part (2) from which a number of spring elements (3, 3') protrude in the direction of the areas of a workpiece to be gripped, the spring elements (3, 3') are designed to be elastically yielding and are arranged with at least one section angled to the base part (2) and to the areas of the workpiece to be gripped, the workpiece-side ends of the spring elements (3, 3') can be brought into contact with the areas of the workpiece to be gripped for gripping in such a way that the spring elements (3, 3') are elastically deformed and apply a clamping force to the workpiece and hold the workpiece in a non-positive manner, and to release the workpiece, the spring elements (3,3') are movable relative to the areas of the workpiece to be gripped in such a way that the clamping force on the workpiece is reduced and the workpiece and gripping device (1) separate from each other.

Description

[0001] The invention relates to a gripping device for the force-locking gripping or positioning of components, in particular a gripper for gripping workpieces according to the preamble of claim 1 and a centering device according to the preamble of claim 21.

[0002] The automated gripping of components or workpieces, or the positioning of workpieces relative to one another, for example, during machining operations, usually requires precise positioning of the workpieces relative to, for example, the gripping elements of a robot or other automated device. Only then can it be guaranteed that the intended interaction between the gripping element and the workpiece is achieved in such a way that the workpiece is securely attached to the gripper, for example, so that it can be moved or machined. It is also often necessary to position two or more workpieces relative to one another so that they assume and maintain a proper position relative to one another.

[0003] For such tasks, grippers or centering devices are used, for example, which are manufactured to fit the workpiece to be gripped or positioned precisely, or which can be adjusted relative to the workpiece to be gripped or positioned. Numerous gripper designs are known from the state of the art. Grippers with mutually adjustable gripper jaws are capable of gripping workpieces precisely, but they are often driven by a complicated lever mechanism and a pneumatic cylinder or similar. Their design is therefore complex and expensive. The gripper and workpiece must also be precisely positioned relative to one another in advance so that the gripping process can proceed as intended. Inaccuracies here can hinder or even completely prevent the precise gripping of the workpiece.It is therefore advantageous if a gripper has a certain degree of flexibility or compensates for inaccuracies or does not hinder the gripping process.

[0004] Vacuum grippers require negative pressure and can only grip smooth and largely airtight surfaces. There are numerous other gripper designs that are also complex and expensive.

[0005] Elastic grippers, such as brushes, have the advantage that they enable gripping even when the workpiece / gripper are not precisely aligned due to the flexibility of the gripping elements. However, they have the disadvantage that a relatively high preload force must be present between the workpiece and the gripping elements to grip the workpiece, and this high preload force must also be overcome when the gripper needs to be pulled out of or off the workpiece.

[0006] From DE 20 2017 104 827 U1, DE 20 2014 103 714 U1, DE 20 2014 101 499 U1, DE 20 2007 003 334 U1, US 2008 / 0 041 196 A1 and US 4 938 107 A, solutions from the field of screw technology are known, in which adaptable torque transmitters with a clamping effect for screwing purposes are specified, which allow easy adaptation to different dimensions of screws and screwing tools.

[0007] The object of the present invention is therefore to provide a cost-effective gripping device or a centering device which is capable of gripping a workpiece quickly and easily or of quickly positioning workpieces relative to one another and, in the process, of centering them and also of easily releasing them again.

[0008] The solution to the problem according to the invention results from the characterizing features of claim 1 with regard to the gripping device and from the

[0009] Centering device comprising the characterizing features of claim 21, each in conjunction with the features of the corresponding preamble. Further advantageous embodiments of the invention emerge from the subclaims.

[0010] The invention is based on a generic gripping device for the non-positive gripping of components, in particular grippers for gripping prismatic workpieces, wherein the gripping device has elastic, protruding elements.Such a gripping device is further developed according to the invention in that the gripping device has a base part from which a number of spring elements protrude in the direction of the areas of a workpiece to be gripped, the spring elements are designed to be elastically flexible and are arranged with at least one section angled to the base part and to the areas of the workpiece to be gripped, wherein the workpiece-side ends of the spring elements are brought into contact with the areas of the workpiece to be gripped for gripping in such a way that the spring elements, while elastically deformed, apply a clamping force to the workpiece and hold the workpiece in a force-fitting manner, and in order to release the workpiece, the spring elements are movable relative to the areas of the workpiece to be gripped in such a way that the clamping force on the workpiece is reduced and the workpiece and the device separate from one another.The spring elements form an elastic intermediate element between the base part, which can be moved, for example, by an automated handling device such as a robot or similar, and the workpiece. The spring elements are elastically deformed upon contact with the workpiece and thus exert a total clamping force on the workpiece. With appropriate design and arrangement of the spring elements relative to the workpiece, this clamping force of the spring elements can be so great that the workpiece can be securely held to the base part by the elasticity of the spring elements alone and can be handled, for example, by a robot. The spring elements are designed in such a way that the clamping force, for example,to release the workpiece can be reduced or largely eliminated by simply moving the base part relative to the workpiece changing the deformation of the spring elements in such a way that the force of the spring elements is no longer sufficient to hold the workpiece, causing the gripper to release the workpiece. Likewise, by moving the base part relative to the workpiece in the other direction, the deformation of the spring elements can be influenced in such a way that the spring elements are tensioned more strongly, thereby increasing the overall clamping force. This makes it possible to create an elastically flexible but secure holding of the workpiece on the gripping device without complex mechanics and drives, which can then be canceled again by simply rotating the base part relative to the workpiece in order to release the workpiece from the gripper.In this invention, a prismatic workpiece or workpiece area is understood to mean not only ideally prismatic sections of workpieces but also workpieces or workpiece areas which, for example, due to the manufacturing technology (e.g. casting bevels or surface roughness) or natural growth form, have a non-significant deviation from an ideally prismatic shape, provided that the deviations from the ideally prismatic shape can be compensated by the elastically protruding elements.

[0011] In an advantageous further development, it is conceivable that the spring elements are angled to the base part and the areas of the workpiece to be gripped in such a way that when the base part is rotated in one direction, the spring elements press against the workpiece in a clamping manner like a freewheel, while in the other direction the workpiece can rotate relative to the spring elements. The spring elements are not aligned largely radially and bendably to a holder, as is the case with a brush gripper, for example, but rather they have a preferred orientation that is angled to the base part. As a result, the spring elements exhibit different behavior when they interact with the walls of the workpiece to be gripped.In one direction of rotation of a relative rotation between the base part and the workpiece, the spring elements are deformed further in the opposite direction to their angular position, just like in a freewheel, and are therefore pressed more firmly against the walls of the workpiece to be gripped, increasing the clamping force of the spring elements and thus of the gripper as a whole. In the other direction of rotation, however, the spring elements relax and the clamping force decreases again. The design of the spring elements can ensure that in this gripping state the clamping force is no longer sufficient to hold the workpiece securely and the workpiece can therefore be released from the gripper again. In other words, the workpiece can be gripped by the base part and the spring elements being assigned to the walls of the workpiece to be gripped, e.g. by linear insertion into an opening in the workpiece.The spring elements are deformed at least slightly and thus exert a total force on the workpiece, which is usually not sufficient for secure gripping. The base part is then rotated relative to the workpiece in such a way that the spring elements spread out due to their angled orientation and contact with the wall of the area of ​​the workpiece to be gripped. Like a freewheel, but with a stronger elastic force, they are pressed against the walls of the workpiece to be gripped and become tense or jammed between the base part and the walls. This increases the resulting clamping force of the spring elements to such an extent that the clamping force required, for example, to handle the workpiece is exceeded and the workpiece is securely fastened to the gripping device.This clamping effect of the spring elements can also be designed so that the clamping effect is maintained after the described tensioning of the spring elements, and the workpiece cannot automatically detach from the gripper. Once the handling or processing task is completed, the workpiece can be released from the gripper by rotating the base part back relative to the workpiece, which relaxes the spring elements and reduces the required clamping force.

[0012] For this purpose, in a further embodiment, the base part and the spring elements arranged thereon are arranged so as to be rotatable and / or linearly displaceable relative to the workpiece. The base part and spring elements can be pushed into a suitable opening in the workpiece, for example by a linear movement, and the spring elements can be elastically deformed somewhat by contact with the walls of the opening in the workpiece. The base part is then rotated relative to the walls of the opening in the workpiece into a clamped position, whereby the spring elements arranged at an angle between the walls and the base part are elastically deformed and pressed more strongly against the walls of the opening in the workpiece. Overall, the necessary clamping force is reached and exceeded. This means, for example, that a handling device to which the base part is attached can pick up and hold the workpiece.After the machining operation, the workpiece is released again by rotating the base part in the other direction relative to the workpiece and the spring elements relax again, whereby the necessary clamping force is undershot and the workpiece is released linearly from the gripper, e.g. by the effect of gravity.

[0013] It is also conceivable for the cross-section of the base part to be round or rectangular or adapted to the sections of the workpiece to be gripped. The cross-sectional shape of the base part adapts to the shape of the sections of the workpiece to be gripped. If, for example, a workpiece is to be gripped in a round hole, the base part and thus also the spring elements will also essentially form a round arrangement. In the case of a rectangular opening, on the other hand, the base part will also have at least a rectangular cross-section. When gripping a workpiece from the outside using surrounding contours, the cross-sectional shape of the base part can also be designed to match the design of the area of ​​the workpiece to be gripped and can therefore be very diverse.

[0014] It is also advantageous if the dimensions of the elastically flexible spring elements in their undeformed state are designed such that the spring elements are elastically deformed when brought into contact with the areas of the workpiece to be gripped. The spring elements arranged on the base part must therefore, for example, be pushed linearly against a certain resistance into the interior of an opening to be gripped or over an outer area of ​​a workpiece to be gripped, as a result of which they deform at least slightly. This ensures, however, that the spring elements rest against the walls of the workpiece to be gripped during a subsequent relative rotation between the base part and the workpiece and do not slip freely during the rotation, but rather that the described locking effect can build up.

[0015] In a further embodiment, the spring elements can have a helically twisted extension along the circumference of the base part in the longitudinal direction of the base part, essentially along its axis of symmetry. Due to their helically twisted design, the spring elements adhere particularly well to the walls of the workpiece to be gripped, even if these walls are irregularly shaped. Furthermore, helically twisted spring elements center themselves better in openings of a workpiece, thus ensuring the reliable application of the necessary clamping forces.

[0016] To improve the insertion of the fixture into openings in the workpiece or when aligning the fixture with the outer contours of the workpiece, it can be advantageous to provide a bevel or similar joining aid at the ends of the spring elements intended for joining to the workpiece and protruding from the base part. This facilitates the preferably linear joining of the fixture and workpiece. This allows the spring elements to more easily engage the corresponding sections of the workpiece during insertion, making insertion safer and easier.

[0017] In a first embodiment for use in gripping workpieces in openings of the workpiece, it is conceivable for the base part to be arranged centrally and for the spring elements to be designed with at least one component projecting radially outward from the base part in order to hold workpieces in opening areas such as apertures, holes, or the like. The base part itself can be round or regularly or irregularly shaped to adapt to the opening cross-section. The spring elements are arranged on the outside of the base part.

[0018] In another embodiment for use in gripping workpieces at outer sections of the workpiece, it is conceivable for the base part to be arranged in a ring-shaped manner on the outside, and for the spring elements to be designed with at least one component projecting radially inward from the outer base part in order to hold workpieces at their outer contours. Here, too, the cross-sectional shape of the base part can be adapted to the gripping situation on the workpiece, as already stated, with the spring elements arranged on the inside of the base part being slipped over the workpiece and pressed against the outer contours of the workpiece.

[0019] However, it is also conceivable for spring elements to be arranged on an externally arranged base part, both inside and outside the base part, to hold workpieces at opening areas and / or at outer contours with a gripping device. Such a combination base part can then be used more variably depending on its dimensions.

[0020] Furthermore, it is conceivable that the spring elements not only have a cross-section that remains constant in the radial direction, but that the spring elements have at least one discontinuous or curved cross-sectional section and / or a joint, in which one section of the spring element protrudes at an angle from another section. This can significantly influence the deformation behavior of the spring elements and adapt them to the respective gripping situation. Discontinuous spring elements, i.e. elements with kinks or joints in their cross-section, have many possibilities in their deformation behavior to influence and optimize the elastic deformation and the contact of the spring elements with the sections of the workpiece to be gripped. For example,This can be achieved by ensuring that the spring elements are applied to the sections of the workpiece to be gripped over a larger area or in a more linear manner, thereby influencing the force transmission between the spring elements and the walls via elastic forces and friction.

[0021] It is also conceivable for spring elements with opposing helical twists to be arranged simultaneously on a base part, which provide a locking effect of the spring elements in both directions of rotation of the fixture relative to the workpiece. While this makes inserting and removing the fixture from the workpiece more difficult, it simultaneously improves the retention of the workpiece on the fixture.

[0022] It is also conceivable to simultaneously arrange spring elements with different spring cross-sections and / or spring shapes on a base part in order to adapt the gripping device to complex or asymmetrical gripping geometries of the workpiece. The different spring cross-sections and spring shapes can, for example, improve gripping in square openings by placing different spring elements in the corners of the opening than in the straight wall areas in between.

[0023] It is also conceivable for the base part and / or the helically twisted spring elements to be designed in segments, and for several segments to be arranged in a combinable manner on the gripping device. This creates a kind of modular gripper system in which the segments are combined to form a suitable device depending on the shape and dimensions of the workpiece sections to be gripped. Here, too, it is conceivable for the helical twist of the spring elements of the individual segments to be designed differently or in opposite directions.

[0024] Further adaptability of the gripping device can be achieved by having the spring elements and / or the base part made of different materials. For example, the base part and spring elements can be constructed from different materials, but it is also conceivable to equip individual spring elements from different materials or with different elasticities. For this purpose, it is further advantageous if the spring elements and / or the base part are non-positively connected to one another, as this allows individual spring elements to be easily replaced and modified.

[0025] However, it is also conceivable that the gripping device is manufactured by additive processes, preferably by FLM processes and / or by extrusion and / or by injection molding or casting.

[0026] The invention further relates to a centering device for centering and positioning workpieces relative to one another at prismatic openings or outer contours, in which the centering device has a central base part from which a number of spring elements protrude in the direction of the walls of the openings to be positioned or outer contours of the workpieces, the spring elements are designed to be elastically flexible and are arranged at an angle to the central base part and to the walls of the openings or outer contours of the workpieces to be positioned, and the workpiece-side ends of the spring elements can be inserted or plugged into the openings to be centered or onto the outer contours of the workpieces for positioning in such a way that the spring elements, when elastically deformed, apply a centering force to the workpieces and center the openings or outer contours of the workpieces to be centered relative to one another. Generic centering devices are, for example,in the form of locating pins are used to align the position of two components in bores in such a way that the components can be disassembled again and again and yet precisely reassembled using the locating pins. However, the tolerances and fits of the locating pins must be manufactured with great effort for this purpose. Therefore, due to the elasticity of the spring elements, the centering device according to the invention is used to achieve an assignment of the components to one another that is sufficient for many purposes with far less necessary accuracy. The structure and properties of the gripping device described above can largely be transferred to this purpose as a centering device and express reference is therefore made thereto. In particular, the statements relating to the subclaims can largely also be transferred to the centering device and explicit mention of these properties is avoided here.A centering effect can be achieved either by inserting the centering device into one or more openings of several workpieces, but also by enclosing convex surfaces of several workpieces from the outside, e.g. by arranging shaft components one behind the other, which are then placed on a shaft in an assembly process.

[0027] A particularly preferred embodiment of the gripping device according to the invention is shown in the drawing.

[0028] They show: Fig. 1 - a first embodiment of the gripping device according to the invention with a steep taper holder, axial contact surface and mounting chamfer for insertion aid, designed as a gripper for a round bore, Fig. 2 - another design of the gripping device with continuous right-hand helically wound spring elements with a curved segment as a cross-section, designed as an internal and external gripper, Fig. 3 - another design of the gripping device with continuously left-handed helically wound spring elements with a C-shaped cross-section without a defined articulated joint, designed as an internal and external gripper, Fig. 4 - another embodiment of the gripping device with segmented, left-handed and right-handed (zig-zag) helically wound spring elements with an arc segment as a cross-section, designed as an internal and external gripper, Fig. 5 - a further embodiment of the gripping device with spring elements wound helically on both sides with a curved segment as a cross-section, designed as an internal and external gripper, Fig. 6 - a further embodiment of the gripping device with continuous left-handed, helically wound spring elements with 2-stage disc spring contour with defined articulated joint as cross-section, designed as internal and external gripper, Fig. 7 - another embodiment of the gripping device with segmented, right-handed, helically wound spring elements with an arc segment as a cross-section, designed as an internal and external gripper, Fig. 8 - an example of the use of the gripping device according to the invention when gripping a cylindrical screw head from the outside, Fig. 9 - a plan view of the gripping device during the gripping process, in which three of the five elastically projecting spring elements are visibly in contact with an elliptical bore wall of a workpiece, Fig. 10 - from left to right, three consecutive sub-steps of a centering process for sheet metal components that are difficult to clamp, using two gripping or centering devices, Fig. 11 - an example of the use of the centering device according to the invention when centering two axially arranged pipe segments.

[0029] In the Fig. Figure 1 shows a schematic, three-dimensional representation of the gripping device 1 with a known steep taper mount 5, axial contact surface 4, and mounting chamfer 7 for insertion assistance, as a gripper for a round bore (not shown). A likewise round, approximately bush-like base part 2 is attached to the steep taper mount 5 as an extension of the latter and can be inserted into a machine tool or a handling device such as a robot and thus moved.

[0030] On the outside of the base part 2, and here integrally connected to the base part 2, spring elements 3 made of an elastically deformable material are arranged on the outer circumference of the base part 2. As can be clearly seen in the upper cross-section, these spring elements 3 are angled at an angle and project evenly from the base part 2 in the direction of the bore (not shown) distributed over the entire circumference of the base part 2. The outer envelope of the spring elements 3, which must be matched to the diameter of the bore in the workpiece to be gripped, is indicated by the part number 8.

[0031] The elastic spring elements 3 are angled relative to the circumferential direction of the base part 2 such that when the gripper 1 rotates relative to the workpiece in one direction 10, the elastic spring elements 3 expand upon contact with the workpiece toward the workpiece to be gripped and press against the workpiece, thus increasing the gripping force. When rotated in the other direction 10, however, they move away from the workpiece, thus reducing the gripping force. The elastic spring elements 3 thus function as a freewheel.

[0032] The spring elements 3 not only protrude at an angle from the base part 2, but they are also twisted around the base part 2. The helical twist of the elastic spring elements 3 in the locking direction reinforces the centering effect of the workpiece relative to the gripping axis 11. The twist of the helical shape is adapted to the shape of the elastic spring elements 3 and reinforces the effect of increasing or decreasing the gripping force when rotating the gripping device.

[0033] In one direction of rotation 10 of a relative rotation between the base part 2 and the workpiece, the spring elements 3 are further deformed against their angularity, as in a freewheel, and are thus pressed more firmly against the walls of the workpiece to be gripped, whereby the clamping force of the spring elements 3 and thus of the gripper 1 is increased. In the other direction of rotation 10, however, the spring elements 3 relax and the clamping force decreases again. The design of the spring elements 3 can ensure that in this relaxed gripping state the clamping force is no longer sufficient to hold the workpiece securely and the workpiece can therefore be released again from the gripper 1. In other words, the workpiece can be gripped by the base part 2 and the spring elements 3 being assigned to the walls of the workpiece to be gripped, e.g. by linear insertion in the insertion direction 11 into an opening in the workpiece.In this case, the spring elements 3 are at least slightly deformed by contact with the workpiece and thus exert a total force on the workpiece which, however, is generally not sufficient for secure gripping. The base part 2 is then rotated relative to the workpiece in such a way that the spring elements 3 spread out due to their cross-sectional shape and angled orientation and are pressed against the walls of the workpiece to be gripped, like a freewheel, but with a stronger elastic force. This increases the resulting clamping force of the spring elements 3 to such an extent that the clamping force required, for example, to handle the workpiece is exceeded and the workpiece is securely fastened to the gripping device 1. This clamping effect of the spring elements 3 can also be designed in such a way that the clamping effect is maintained after the described clamping of the spring elements 3 and the workpiece cannot release itself from the gripper 1 again.Once the handling or processing task has been completed, the workpiece can be released again from the gripper 1 by clamping the spring elements 3 by turning back in the direction of rotation 10 of the base part 2 relative to the workpiece, whereby the spring elements 3 relax and the necessary clamping force is undershot.

[0034] Workpieces with openings or protruding elements are gripped by sliding the gripper 1 linearly in direction 11 into the opening or over a protruding element of the workpiece. The elastically protruding spring elements 3 deform and thus centrally fix the workpiece to be gripped. A bevel 7 is located on one insertion end of the elastic spring elements 3, which faces the workpiece, to simplify insertion into an opening or sliding over a protruding element of the workpiece.

[0035] In the design according to Fig. 1, in addition to the cross-sectional areas fixed to the base part 2, bends can be seen in the spring elements 3, which are connected via foil hinges 6 or the like and are angled at an angle to the sections closer to the base part 2. Such a design allows these outer sections of the spring elements 3 to be applied more fully to the walls of the bore of the workpiece, thereby increasing the friction between the spring elements 3 and the walls, which can further increase the clamping force of the gripping device.

[0036] Preferably, but not exclusively, such a gripper 1 can be manufactured cost-effectively using an additive 3D printing process, for example using the FLM process.

[0037] In the Fig. Figures 2 to 7 show various other configurations of the spring elements 3, 3', which can be arranged both inside the base part 2 and outside on the circumference of the base part 2, and can thus be suitable for gripping both in openings and on external contours. The figures differ primarily with regard to the configuration of the spring elements 3 and 3', so the above description also generally applies to these configurations, and only important differences are to be pointed out.

[0038] The Fig. Figure 2 shows a configuration of the gripping device 1 with continuously right-handed, helically wound spring elements 3, 3' with a curved segment as a cross-section, designed as internal and external grippers. In principle, identical spring elements 3' project inwardly and spring elements 3 outwardly from the tubular base part 2. The spring elements 3, 3' have an approximately uniform twist over their entire length and form the envelope 8 outside the base part 2 and the envelope 8' inside the base part 2.

[0039] The Fig. Figure 3 shows another embodiment of the gripping device 1 with continuously left-handed, helically wound spring elements 3, 3' with a C-shaped cross-section without a defined articulated joint, designed as an internal and external gripper. Due to the additional C-shaped design of the spring elements 3, 3', the areas of the spring elements 3, 3' oriented toward the walls of the workpiece lie more flatly against the corresponding walls of the workpiece, increasing the friction between the walls and the spring elements 3, 3'. Furthermore, the spring elements 3, 3' become additionally jammed, as they can unfold more strongly during the relative rotation between the base part 2 and the walls of the workpiece.

[0040] In the Fig. Figure 4 shows an embodiment of the gripping device 1 comprising segmented, left-handed and right-handed (zigzag) helically twisted spring elements 3, 3' with an arc segment as a cross-section, as an internal and external gripper. Here, for example, segment rings 9 are placed onto a continuous base part 2, which in turn carry the spring elements 3, 3' and can interact with the base part 2 and the walls of the workpiece in the manner already described. This makes it possible to provide different twisting directions for the spring elements 3, 3' for each segment, such as alternating left- and right-hand twisted spring elements 3, 3'. This makes it possible to press the spring elements 3, 3' in both the one and the other twisting direction, which can be quite advantageous depending on the gripping situation.

[0041] The Fig. 5 shows a further embodiment of the gripping device 1 with spring elements 3, 3' wound on both sides, left / right, in a helical manner, with an arc segment as a cross-section, designed as an internal and external gripper.

[0042] In the Fig. Figure 6 shows a cross-sectional view of an embodiment of the gripping device 1 with continuously left-handed, helically wound spring elements 3, 3' with a two-stage disc spring contour and a defined articulated joint, as an internal and external gripper. The articulated joint 6 and the disc spring contour ensure particularly strong wedging of the spring elements 3, 3', similar to a freewheel.

[0043] The Fig. 7 shows an embodiment of the gripping device 1 with segmented, right-handed, helically twisted spring elements 3, 3' with an arc segment as a cross-section, as internal and external grippers.

[0044] In the Fig. Figure 8 shows an example of the use of the gripping device 1 according to the invention when gripping a cylindrical screw head 14 of a screw 13 from the outside, once at the top before gripping and at the bottom in the gripped state. The gripping device 1 has an external, here round, cup-like base part 2 on a steep cone 5, from which spring elements 3 protrude inwards for interaction with the screw head 14. The screw 13 is then inserted axially with the screw head 14 first into the area of ​​the spring elements 3 or the base part 2 with the spring elements 3 is slipped over the screw head 14, as can be seen in the lower illustration. The spring elements 3 deform in the manner already described above and exert a holding force on the screw head 14.By relative rotation between the screw head 14 and the base part 2, this holding force can be increased or reduced by changing the pressure of the spring elements 3 on the screw head 14 in the manner already described.

[0045] In the Fig. 9, a plan view of the gripping device 1 during the gripping process in an opening 8 of a workpiece 15 shows the deformation of the spring elements 3. Due to the elliptical design of the opening 8, three of the five spring elements 3 elastically protruding outwards from the base part 2 visibly form contact with the elliptical opening wall 8. Due to the twisting of the elastic spring elements 3 in the axial direction, all spring elements 3 (not visible) are in contact with the elliptical opening wall 8. The spring elements 3 have joints 6 in the manner already described, which influence the deformation of the spring elements 3. The spring elements 3 are inserted into the opening 8 under the action of force, so that they deform slightly (visible by the transition regions 16 of the three contacting spring elements 3 at the end of the opening 8).By relative rotation between the opening wall 8 and the base part 2, the spring elements 3 can be deformed and thus pressed more or less strongly against the opening wall 8, so that the holding force can be changed. By relative rotation between the opening wall 8 and the base part 2 in the other direction, the holding force can be reduced again.

[0046] The Fig. 10 shows, from left to right, three successive sub-steps of a centering process for sheet metal components 17, 18 that are difficult to clamp using two centering devices 19. The top two rows show, from left to right, three successive sub-steps for the sheet metal components 17, 18 that are difficult to clamp using two centering devices 19. On the left, the sheet metal components 17, 18 are shown before centering, in the middle the insertion of the centering devices 19 into the first sheet metal component 18 and on the right the insertion of the centering devices 19 into the second sheet metal component 17 and thus the completion of the centering process in the sheet metal plane, each once at the top in a side view and below in a three-dimensional representation.The centering devices 19 serve to ensure elastic and sufficiently precise positioning and centering of the sheet metal components 17, 18 relative to one another, which would otherwise be much more complex, for example, using dowel pins.

[0047] In the Fig. 11 shows a further example of the use of the centering device 19 according to the invention when centering two axially arranged pipe segments 20, 21, in which the centering device 19 is inserted in the axial direction into the ends of the two pipe segments 20, 21 and centers and fixes these ends of the two pipe segments 20, 21 relative to one another.

[0048] According to the principle described above, grippers 1 can also be designed which engage in a square, rectangular or other shaped opening.

[0049] The gripper 1 can be easily inserted into an opening whose inner diameter is smaller than the outer diameter of the gripper 1. As a result, the elastic spring elements 3, 3' deform and apply a preload force that is greater than the weight of the workpiece to be gripped. The workpiece can then be lifted or transported in another way, for example. If the workpiece is set down and held in place, the gripper 1 can be rotated in a direction such that a force is exerted on the elastic spring elements 3, 3', deforming the elastic spring elements 3, 3' inward and thereby reducing the preload. The gripper 1 can now be pulled out of the workpiece with relatively little force. If the workpiece has a certain mass inertia, the gripper 1 can also be rotated so quickly that the elastic spring elements 3, 3' are deformed inward. The workpiece then does not need to be held.

[0050] The gripper 1 can cover a certain size range of openings or protruding cylindrical elements, depending on the elasticity of the elastic spring elements 3, 3'. For a wider size range, different grippers 1 are required, but this is unproblematic due to the simple design and the resulting low cost.

[0051] The gripping device 1 can also be used as an assembly aid, for example for gripping screw heads and for screwing in screws.

[0052] The invention may comprise various embodiments that may be implemented individually or in combination: • External / internal spring elements: The gripping device 1 can have both outer spring elements 3 and inner spring elements 3'. These can be used individually or in combination to optimize adaptation to different geometries. • Segmental spiral: The spiral twist of the spring elements 3, 3' can be implemented in segments. The gripping device 1 can therefore also be manufactured in segments and be modular. • Variable spiral direction: The direction of the spiral twisting of the spring elements 3, 3' can vary, for example in the form of a zigzag pattern • Multiple joints: The spring elements 3, 3' can have more than one joint. The design of these joints is not limited to a specific shape, but can include various geometries. • Counter-rotating windings: Within a gripping device 1, spring elements 3, 3' with opposing winding directions can be combined. This improves the centering effect and increases the stability of the grip. • Double-sided blocking effect: The gripping device 1 can be designed to have a locking effect in both directions along the gripping axis 11. This enables secure fixation of the gripped workpiece in the axial direction. (Follows from variable spiral direction and counter-rotating windings) • Heterogeneous shapes of the spring elements 3, 3': Different spring elements 3, 3' can be combined within a gripping device 1. This allows optimal adaptation to complex or asymmetrical geometries • Number of spring elements 3, 3': The number of spring elements 3, 3' is preferably designed as a prime number. This prevents certain geometries from systematically disrupting the centering effect. • Heterogeneous material: The spring elements 3, 3' can be made of a wide variety of materials. This allows for influencing the spring behavior, such as spring force, spring travel, and strength. A non-material connection between the spring elements 3, 3' and the base part 2 is conceivable. This results in interchangeability and modularity of the system.

[0053] The following manufacturing processes are possible for the gripping device: • Additive processes: FLM / SLS / SLA / SLM • Extrusion: Metals / Thermoplastics • Injection molding / casting: thermosets, thermoplastics, metals

[0054] Use as a centering pin: • Can be used to align parts in an axis with one pin, in a plane with two pins, or in space with three pins • The pin can be inserted into / over protruding / projecting component features and centers the feature to the core axis of the pin • Deviations in the roundness / cylindricity of the element to be centered do not significantly influence the centering effect • A rotation of the centering pin in / on the element to be centered against the locking direction promotes centering, as the spring bodies can settle Part number list 1 gripping device, gripper 2 Base part 3, 3' spring elements 4 contact surface 5 Steep taper holder 6 joint 7 slopes 8, 8' Envelope / opening wall 9 segments 10 Direction of rotation 11 Joining direction 12 Centering device 13 Screw 14 screw head 15 Workpiece 16 Transition area deformed / undeformed area of ​​the spring elements 17 Sheet metal part 18 sheet metal part 19 Centering device 20 pipe segments 21 pipe segment

Claims

[1] Gripping device (1) for the force-locking gripping of components, in particular gripping device (1) for gripping prismatic workpieces, wherein the gripping device (1) has elastic projecting elements (3, 3'), characterized by , that the gripping device (1) has a base part (2) from which a number of spring elements (3, 3') protrude in the direction of the areas of a workpiece to be gripped, the spring elements (3, 3') are designed to be elastically flexible and are arranged with at least one section angled to the base part (2) and to the areas of the workpiece to be gripped, the workpiece-side ends of the spring elements (3, 3') can be brought into contact with the areas of the workpiece to be gripped in such a way that the spring elements (3, 3') are elastically deformed, apply a clamping force to the workpiece and hold the workpiece in a force-fitting manner, to release the workpiece, the spring elements (3, 3') are movable relative to the areas of the workpiece to be gripped in such a way that the clamping force on the workpiece is reduced and the workpiece and gripping device (1) separate from each other. [2] Gripping device (1) according to claim 1, characterized by that the spring elements (3, 3') are angled to the base part (2) and to the areas of the workpiece to be gripped in such a way that when the base part (2) is rotated in one direction, the spring elements (3, 3') press against the workpiece in a clamping manner like a freewheel, and in the other direction the workpiece can be rotated relative to the spring elements (3, 3'). [3] Gripping device (1) according to claim 2, characterized bythat the arrangement of the spring elements (3, 3') aligned at an angle to the base part (2) and to the areas of the workpiece to be gripped causes a spreading of the spring elements (3, 3') and an increase in the clamping force in the event of a relative rotation (10) between the gripping device (1) and the workpiece in one direction, and a relative rotation in the other direction causes a reduction in the clamping force. [4] Gripping device (1) according to one of the preceding claims, characterized by that the base part (2) and the spring elements (3, 3') arranged thereon are arranged so as to be rotatable and / or linearly displaceable relative to the workpiece. [5] Gripping device (1) according to one of the preceding claims, characterized by that the cross-section of the base part (2) is round or rectangular or adapted to the sections of the workpiece to be gripped. [6] Gripping device (1) according to one of the preceding claims, characterized bythat the dimensions of the elastically flexible spring elements (3, 3') in the undeformed state are designed such that the spring elements (3, 3') are elastically deformed when brought into contact with the areas of the workpiece to be gripped. [7] Gripping device (1) according to one of the preceding claims, characterized by that the joining of the workpiece and gripping device (1) takes place in a linear direction (11), preferably by a linear insertion or attachment of the gripping device (1) relative to the workpiece. [8] Gripping device (1) according to one of the preceding claims, characterized by that the spring elements (3, 3') in the longitudinal direction (11) of the base part (2) have a helically twisted extension on the circumference of the base part (2) essentially along its axis of symmetry (11). [9] Gripping device (1) according to one of the preceding claims, characterized bythat a bevel (7) or similar joining aid is arranged on the ends of the spring elements (3, 3') intended for joining to the workpiece and projecting from the base part (2), which facilitates the preferably linear plugging together of the gripping device (1) and the workpiece. [10] Gripping device (1) according to one of the preceding claims, characterized by that the base part (2) is arranged centrally and the spring elements (3, 3') are designed with at least one component projecting radially outwards from the base part (2) in order to hold workpieces at opening areas such as openings, bores or the like. [11] Gripping device (1) according to one of claims 1 to 9, characterized by that the base part (2) is arranged in an annular manner on the outside and the spring elements (3, 3') are designed with at least one component projecting radially inwards from the outer base part (2) in order to hold workpieces at their outer contours. [12] Gripping device (1) according to claim 11, characterized by that spring elements (3, 3') are arranged on an externally arranged base part (2) both on the inside and on the outside of the base part (2) in order to hold workpieces both on opening areas and / or on outer contours. [13] Gripping device (1) according to one of the preceding claims, characterized by that the spring elements (3, 3') have at least one discontinuous or curved cross-sectional section and / or a joint (6), in which a section of the spring element (3, 3') protrudes at an angle from another section. [14] Gripping device (1) according to one of the preceding claims, characterized bythat spring elements (3, 3') of opposite helical twisting are arranged simultaneously on a base part (2), which cause a blocking effect of the spring elements (3, 3') in both relative directions of rotation (10) of the gripping device (1) relative to the workpiece. [15] Gripping device (1) according to one of the preceding claims, characterized by that spring elements (3, 3') of different spring cross-sections and / or spring shapes are arranged simultaneously on a base part (2) in order to adapt the gripping device (1) to complex or asymmetrical gripping geometries of the workpiece. [16] Gripping device (1) according to one of the preceding claims, characterized by that the base part (2) and / or the helically twisted spring elements (3, 3') are formed in segments and several segments (9) are arranged in a combinable manner on the gripping device (1). [17] Gripping device (1) according to claim 16, characterized bythat the helical twisting of the spring elements (3, 3') of the individual segments (9) is different or opposite. [18] Gripping device (1) according to one of the preceding claims, characterized by that the spring elements (3, 3') and / or the base part (2) have different materials. [19] Gripping device (1) according to one of the preceding claims, characterized by that the spring elements (3, 3') and / or the base part (2) are fixed to one another in a force-fitting manner. [20] Gripping device (1) according to one of the preceding claims, characterized by that the gripping device (1) can be produced by additive processes, preferably by FLM processes, and / or by extrusion and / or by injection molding or casting. [21] Centering device (12) for centering and positioning workpieces relative to each other at prismatic openings or prismatic outer contours, wherein the centering device (12) has a central base part (2) from which a number of spring elements (3) protrude in the direction of the walls of the openings or outer contours of the workpieces to be positioned, the spring elements (3) are elastically flexible and are arranged at an angle to the central base part (2) and to the walls of the openings or outer contours of the workpieces to be positioned, the workpiece-side ends of the spring elements (3) can be inserted or plugged into the openings to be centered or around the outer contours of the workpieces for positioning in such a way that the spring elements (3) are elastically deformed, apply a centering force to the workpieces and center the openings to be centered or outer contours of the workpieces relative to one another. characterized by , that To separate the workpieces, the spring elements (3) are movable relative to the areas of the workpieces to be centered in such a way that the centering force on the workpieces is reduced and the workpiece and the centering device (12) separate from each other. [22] Centering device (12) according to claim 21, characterized by that in order to separate the workpieces, the central base part (2) can be rotated relative to the openings or outer contours of the workpieces to be centered in such a way that the centering force on the workpieces is reduced and the workpieces can be separated from one another. [23] Centering device (12) according to one of claims 21 or 22, characterized bythat the arrangement of the spring elements (3) which is angled to the base part (2) and to the areas of the workpiece to be gripped causes a spreading of the spring elements (3) and an increase in the clamping force when there is a relative rotation between the centering device (12) and the workpieces in one direction, and a relative rotation in the other direction causes a reduction in the clamping force. [24] Centering device (12) according to one of claims 21 to 23, characterized by that the spring elements (3) in the longitudinal direction of the base part (2) have a helically twisted extension on the circumference of the base part (2) along its axis of symmetry. [25] Centering device (12) according to one of claims 21 to 24, characterized bythat the spring elements (3) have at least one discontinuous or curved cross-sectional section and / or a joint (6), in which a section of the spring element (3) protrudes at an angle from another section. [26] Centering device (12) according to one of claims 21 to 25, characterized by that the spring elements (3) compensate for inaccuracies or differences in the openings to be centered or the outer contours of the workpieces through their elasticity. [27] Centering device (12) according to one of claims 21 to 26, characterized by that a rotation of the centering device (12) against the locking effect of the spring elements (3) improves the centering of the workpieces.

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