Gripping device for a robot

Abstract

Gripping device (36) for a robot, comprising at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) which can be movably fastened to at least one base plate (38) of the robot and at least one functional element (10) is movably mounted on the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) by means of at least one bearing element (12), so that the at least one functional element (10) can be flexibly adapted to the structure of an object to be gripped, characterized in that the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) is reversibly angularly adjustable in at least one direction with respect to a rest position that can be defined by a user, and in that the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) is reversibly adjustable in length in at least one direction relative to a rest position defined by a user.

Description

[0001] The invention relates to a gripping device for a robot.

[0002] In current production in car body construction, components are assembled into a raw component in several process steps. It is common practice to manufacture different types in one system. Each robot therefore requires the corresponding type-specific process grippers, including the appropriate docking system. When a type changes during production, each gripper must be converted or redocked. These operations require valuable cycle time. Furthermore, the large number of docking and gripping systems results in a type-dependent form of additional investment, which is noticeable not only in resource planning but also in design work. Another aspect is the large amount of space required when using three or more types. The robot has only a limited reach, and therefore the transfer and process stations must be located nearby.If three or more docking systems, including the appropriate gripping devices, are positioned within reach of the robot in this limited space, there is a risk that operations such as gluing, spot welding, and turning cannot be performed safely. The robot's freedom of movement is limited by the multitude of operating devices. Various concepts are already known from the state of the art that focus on more flexible handling of gripping elements and their associated components.

[0003] For example, DE 20 2016 101 750 U1 discloses a gripper for gripping a part or component. Such a gripper comprises a coupling component with which the gripper can be connected to an actuator. The gripper has its own power transmission device, allowing the gripper to be switched via at least one functional element of the gripper. Such a gripper therefore requires no external hoses and lines for supplying energy and other operating resources. A particular configuration of the gripper with respect to the structure of an object to be gripped is not explicitly mentioned.

[0004] The document DE 10 2013 218 765 A1 discloses a gripping mechanism. It comprises at least three gripping elements, which are jointly designed to grip an object. While different geometries of objects can thus be gripped by the gripping mechanism, a separate position of the object to be gripped relative to the gripping mechanism is not provided. The alignment of one gripping element is always achieved relative to the corresponding alignments of the other gripping elements. A gripping element alone can therefore only partially accomplish the task associated with this technical solution.

[0005] DE 10 2005 022 887 A1 discloses a device for aligning and holding at least two-dimensionally deformed components, as well as a method for operating the device. Several height-adjustable holding elements are provided, along with separately movable positioning elements. Only the interaction between these components ultimately enables the alignment and holding of an object, for example, a sheet metal part.

[0006] WO 2010 / 135788 A1 discloses magnetically switchable tools for use with a workpiece or a tool holder and as a clamping device for machining or welding processes. At least two permanent magnets are provided, which are movable to selectively generate an external magnetic field and a magnetic flux path through the pole pieces when they are in contact with a ferromagnetic workpiece. Furthermore, two pole extension elements are provided, which have at least two engagement surfaces for bringing into contact with two workpieces. The engagement surfaces have contours that partially correspond to differently shaped workpieces, for example, a curved or a straight workpiece. However, the mounting of the workpiece to be treated can only be influenced to a limited extent.

[0007] The invention is based on the object of providing a gripping device which has a high degree of flexibility in its field of application at low cost.

[0008] In a preferred embodiment of the invention, it is provided that a gripping device for a robot is provided. This device comprises at least one adjustable axis which can be movably fastened to at least one base plate of the robot, wherein at least one functional element is movably mounted on the at least one adjustable axis by means of at least one bearing element, such that the at least one functional element can be flexibly adapted to the structure of an object to be gripped. Such a flexible gripping device or such a flexible robot gripper is capable of gripping geometrically different components and carrying out processes reliably. The gripper adapts to the structures of an object, for example a component, in order to be able to grip reliably. The gripping device provides a high level of flexibility, while the technical complexity is low.In the simplest case, only a single adjustable axis is provided. Depending on the process requirements, additional axes can be added. This gripping device is therefore fully flexible and contributes to cost, space, and design time savings.

[0009] Furthermore, the invention provides that the at least one adjustable axis is reversibly angle-adjustable in at least one direction relative to a user-definable rest position. Depending on the structure of the object to be grasped, particularly flexible adjustment is thus possible. Any direction is conceivable, with a reversible setting also being possible in each case.

[0010] Furthermore, the invention provides that the at least one adjustable axis is reversibly adjustable in length in at least one direction relative to a user-definable rest position. Especially when the size of the objects to be gripped varies, the high flexibility of the gripping device allows for immediate response.

[0011] Further preferred embodiments of the invention emerge from the remaining features mentioned in the subclaims.

[0012] In a further preferred embodiment of the invention, the at least one bearing element comprises a gimbal suspension. A functional element mounted in this manner is particularly well adaptable to the structure of the objects to be gripped.

[0013] Furthermore, in a preferred embodiment of the invention, the gripping device comprises at least one electric motor that can be coupled to the at least one functional element, wherein the at least one functional element is mounted on the at least one adjustable axis in an electrically adjustable manner by means of the at least one electric motor. This allows for additional flexibility. For example, the at least one functional element can be designed to be height-adjustable relative to a rest position of the at least one adjustable axis. Such a gripping device can also be referred to as an E-Flex gripper.

[0014] A preferred embodiment of the invention also provides that the at least one functional element comprises an electrically switchable permanent magnet element and that the functional element comprises at least one alignment element which is designed to automatically position the permanent magnet element in relation to a surface of an object to be gripped upon contact with the object. This embodiment is therefore designed for objects or components to be gripped that are magnetic. The alignment element can, for example, be a soft element which thus flexibly aligns the magnet into the correct position when it is placed on the component. Such a gripping device is therefore even more flexible and can adapt even better to the structure of the object to be gripped. It is also conceivable for the alignment element to be used independently of the permanent magnet element.The permanent magnet element can be constructed essentially from a single component or from multiple parts made up of different components. In a special case, a permanent magnet element according to the basic principle of the magnet presented in WO 2010 / 135788 A1 could also be used. In combination with the bearing and design provided in the gripping device presented, a particularly flexible gripping device can be provided that is significantly improved compared to the aforementioned prior art, since very flexible adaptation to the structure of the object to be gripped is possible.

[0015] Furthermore, a preferred embodiment of the invention provides that the at least one functional element comprises a vacuum suction cup. This allows even non-magnetic objects to be gripped or suctioned. Such a gripping device is also very flexible and can adapt particularly well to the structure of the object to be gripped.

[0016] Furthermore, a preferred embodiment of the invention provides that, in the case of at least two adjustable axes and at least two functional elements, only one functional element is designed to be electrically adjustable by means of the at least one electric motor, or that at least one functional element is designed to be electrically adjustable by means of the at least one electric motor. In other words, depending on the structure of the object, a corresponding orientation and adjustability of the gripping device can be provided, so that particularly high flexibility can be achieved with low effort.

[0017] A preferred embodiment of the invention also provides for the bearing element to be reversibly pivotable at an angle of up to 15° in at least two opposing directions relative to a user-definable rest position. Such a gripping device is thus even more flexible and can adapt even better to the structure of the object to be gripped.

[0018] A preferred embodiment of the invention also provides for the at least one adjustable axis to be reversibly angle-adjustable in at least two directions relative to a user-definable rest position, with the two directions being oriented at right angles to each other. Thus, a device can be constructed with manageable effort while still achieving a high degree of flexibility.

[0019] In general, the gripping device presented can be used for production in a company, whereby such production can, for example, represent a body shop or general assembly.

[0020] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0021] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a perspective view of a functional element with a bearing element of a gripping device; Fig. 2 a schematic plan view of a gripping device; Fig. 3 a schematic representation of a height-adjustable functional element with a bearing element of a gripping device; Fig. 4 a schematic plan view of two adjustable axes of a gripping device; Fig. 5 a schematic side view of an adjustable axis of a gripping device; Fig. 6 a schematic plan view of four adjustable axes of a gripping device.

[0022] Fig. 1 shows a perspective view of a functional element 10 with a bearing element 12 of a gripping device 36. The functional element 10 is a magnetic permanent magnet element which is mounted on an associated switching device 14. This switching device 14 can also be regarded as a special component of the magnetic permanent magnet element. The magnetic permanent magnet element is essentially cylindrical and comprises an essentially cylindrical main body 16 and an essentially cylindrical collar element 18. The cylindrical main body 16 has an essentially flat contact surface 17. The contact surface 17 is thus designed to come into contact with a structure or a surface of an object or component to be gripped, so that this magnetic component can be gripped when the magnet is activated.The main body 16 is arranged on the cylindrical collar element 18 or can form a structural unit therewith. In the illustration shown, a locking element 20 is shown on the collar element 18, which engages in a groove 22 provided for this purpose in the switching device 14. An alignment element (not shown) or a soft element could also be provided so that the magnet could be provided with even better alignment. The switching device 14 is also essentially cylindrical. However, it is also conceivable that the aforementioned geometries deviate from the aforementioned shapes, where appropriate. The switching device 14 is longer than the main body 16, with an upper end 24 in which the groove 22 is provided having an identical outer radius to that of the collar element 18.On the opposite side of the upper end 24, the switching device 14 and thus indirectly also the magnetic permanent magnet element or the functional element 10 are received by the bearing element 12. In this case, the bearing element 12 is a gimbal suspension and comprises two ring elements 26A, 26B, which have a common support point 28. The two ring elements 26A, 26B overlap, with the ring element 26A being movably mounted in an inner region 30 and the ring element 26B being arranged in an outer region 32. In other words, the ring element 26B extends externally around the ring element 26A, with the two ring elements 26A, 26B being able to change their position independently of one another around a pivot point of the common support point 28. The ring element 26A surrounds at least two jaw elements 34, which are located to the left and right in the inner region 30 of the ring element 26A with respect to the image plane.The ring element 26A is arranged on the jaw elements 34 in such a way that a flat contact of the ring element 26A with the two jaw elements 34 is established.

[0023] Fig. 2 shows a schematic plan view of a gripping device 36. This special gripping device 36 has a base plate 38. The base plate 38 has a substantially rectangular shape and has a circular opening 40 in the center. For example, a coupling to a robot (not shown) could be realized using this opening 40. The longer side surfaces 42 of the base plate 38 are located above and below the image plane, wherein these side surfaces 42 are shown mirror-symmetrically and each have a recess at the level of the circular opening 40. In other words, the side surfaces 42 of the base plate 38 are shown tapered at the level of the circular opening 40. From shorter side surfaces 44, axes 46 protrude to the left and right of the base plate 38, respectively. The axes 46 thus extend from the base plate 38 in the right and left directions, respectively, relative to the image plane.Ten smaller holes 47 can be seen on each of the shorter side surfaces 44, which are located at the outer edge of the base plate 38. To the side of the respective holes in the left and right corners of the base plate 38, there are two further smaller holes 47 on each of the side surfaces 42, which are also located in an outer edge area of ​​the base plate 38. The axes 46 are arranged on the base plate 38 or are fastened to the base plate 38 with fastening means not shown in detail. At the respective end pieces 48 of the axes 46, further axes 50A, B, C, D extend upwards and downwards at right angles from the axes 46 with respect to the image plane. The length of the further axes 50A, B, C, D is shorter than the length of the axes 46. Schematically illustrated bearing elements 12 are located at the end of each of the further axes 50A, B, C, D.The bearing element 12 at axis 50D is covered by an electric motor 52 and is therefore not shown in detail. Functional elements 10 are arranged on the respective bearing elements 12, corresponding to the number of bearing elements 12. In this case, the functional elements 10 are shown as magnetic permanent magnet elements. A total of four reinforcing elements 54 can be seen in the inner corner areas between the axes 46 and the respective further axes 50A, B, C, D. These reinforcing elements 54 are arranged so as to lie flat against the axes 50A, B, C, D and are arranged between the axes 50A, B, C, D and the base plate 38. Two reinforcing elements 54 are arranged above and below the image plane on the same axis 46. Thus, for example, a reinforcing element 54 lies at right angles both on a side surface of the axis 50A oriented in the direction of the base plate 38 and on one side of the axis 46.An outer boundary of the reinforcing element 54 runs essentially diagonally between the axis 50A and the axis 46. In other words, each reinforcing element 54 has an essentially triangular shape. Other shapes are conceivable which suitably reinforce or suitably support the connecting corner regions of the axes 46 with the corresponding further axes 50A, B, C, D. All four reinforcing elements 54 have essentially the same shape and are arranged in a similar way in the sense of a functional gripping device 36 in the corresponding regions, in particular in such a way that the full flexibility of the booms is not impaired. The two axes 46 and the further axes 50A, B, C, D each comprise three rail elements 56 with internal elongated holes 58. The number of the respective elongated holes 58 is in the . Fig. 2 is shown only as an example and could have any number of elongated holes 58 that proves useful. The shape of the elongated holes 58 could also be different or differently designed. The number and arrangement of the rail elements 56 with the corresponding elongated holes 58 are shown only as examples and can vary accordingly. It is conceivable, for example, that a larger number of rail elements 56 would be provided for very heavy objects to grip. Using the corresponding elongated holes 58, an axis 46 can be assembled from the individual rail elements 56 according to a modular principle. The length could also be varied in this way.

[0024] Fig. Figure 3 shows a schematic representation of a height-adjustable functional element 10 with a bearing element 12 of a gripping device 36. A further axis 50D is arranged on an axis 46, with the further axis 50D being arranged in a height-adjustable manner on an electric motor 52. A double arrow indicates possible directions of movement.

[0025] A further axis 50E protrudes at right angles from the further axis 50D. A bearing element 12 is arranged on this further axis 50E. A functional element 10 is arranged on the bearing element 12. In this embodiment, the functional element 10 is shown as a magnetic permanent magnet element. In a rest position shown, the bearing element 12 is arranged at right angles to the further axis 50E, wherein the bearing element 12 can be adjusted to the right and left by 15° relative to the image plane, respectively, relative to the rest position. An imaginary pivot point lies approximately above the functional element, again relative to the image plane. Dashed lines indicate a respective maximum adjustment position of the bearing element 12. The axis 46 again comprises three rail elements 56.The further axis 50D is shown only schematically in a substantially rectangular, elongated shape, with the electric motor 52 arranged at the upper end relative to the image plane. The further axis 50E is shown as rod-shaped and comprises round elements 58 at the respective end points. Between the round elements 58 and the arranged bearing element 12, for example designed as a gimbal suspension, there are further round elements 60, which have a smaller radius than the round elements 58 at the end points. The functional element 10 in the form of the magnetic permanent magnet element has a flat contact surface 17, with respective rod elements 62 extending downward from the contact surface 17 relative to the image plane at the edge regions to the left and right of the contact surface 17.

[0026] Fig. 4 shows a schematic plan view of two adjustable axes 46 of a gripping device 36. The axes 46 are mounted on a Fig. 2 described base plate 38. Two positions are shown in each case, whereby the axes 46 can thus be rotated upwards and downwards relative to the image plane by an angle not further described. The two axes 46 are arranged on the base plate 38 in such a way that an adjustment of a respective axis 46 has an opposite effect on the other axis 46. In other words, if the axis 46 on the left is adjusted upwards, the right axis 46 is simultaneously adjusted downwards. In a special form, the two axes 46 could also be incorporated into one axis 46 or into an axis construction or at least be functionally coupled with one another. Such axes 46 can also be referred to as cantilevers. In this Fig. In Figure 4, the axes 46 are shown only schematically without the rail elements 56. In this top view, the axes 46 can be adjusted clockwise or counterclockwise relative to the base plate 38 located in the center.

[0027] Fig. Figure 5 shows a schematic side view of an adjustable axis 46 of a gripping device 36, wherein bearing elements 12 with respective functional elements 10 are arranged at the end points of the adjustable axis 46. Dashed arrows indicate the direction of movement of the adjustable axis 46. This adjustable axis 46 can be adjusted clockwise or counterclockwise around a schematically illustrated pivot point 64 and relative to the schematically illustrated pivot point 64 arranged in the center.

[0028] Fig.Figure 6 shows a schematic top view of four adjustable axes 46 of a gripping device 36. The four adjustable axes 46 are arranged centrally on the four sides of a base plate 38. Extension elements 66 are arranged at the respective ends of the four axes 46. Dashed arrows indicate that the four axes 46 are thus adjustable in length via the extension elements 66. List of reference symbols 10 functional element 12 bearing element 14 Switching device 16 main bodies 17 Contact surface 18 collar element 20 locking element 22 grooves 24 upper end 26A ring element 26B Ring element 28 stopping point 30 inner area 32 outer area 34 jaw element 36 gripping device 38 Base plate 40 Opening 42 side surface 44 shorter side surface 46 Axis 47 holes 48 end piece 50A additional axis 50B additional axis 50C additional axis 50D additional axis 50E additional axle 52 electric motor 54 Reinforcing element 56 rail element 58 elongated holes 60 round element 62 rod element 64 Pivot point 66 extension element

Claims

[1] Gripping device (36) for a robot, comprising at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) which can be movably fastened to at least one base plate (38) of the robot and at least one functional element (10) is movably mounted on the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) by means of at least one bearing element (12), so that the at least one functional element (10) can be flexibly adapted to the structure of an object to be gripped, characterized by that the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) is reversibly angularly adjustable in at least one direction relative to a rest position that can be defined by a user, and that the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) is reversibly length-adjustable in at least one direction relative to a rest position that can be defined by a user. [2] Gripping device (36) according to claim 1, characterized bythat the at least one bearing element (12) comprises a cardanic suspension. [3] Gripping device (36) according to one of the preceding claims, characterized by in that the gripping device (36) comprises at least one electric motor (52) which can be coupled to the at least one functional element (10), wherein the at least one functional element (10) is mounted on the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) in an electrically adjustable manner by means of the at least one electric motor (52). [4] Gripping device (36) according to one of the preceding claims, characterized by that the at least one functional element (10) comprises an electrically switchable permanent magnet element and that the functional element (10) comprises at least one alignment element which is designed to automatically position the permanent magnet element with respect to a surface of the object upon contact with an object to be gripped. [5] Gripping device (36) according to one of the preceding claims 1 to 3, characterized by that the at least one functional element (10) comprises a vacuum suction cup. [6] Gripping device (36) according to one of the preceding claims, characterized by in the case of at least two adjustable axes (46, 50A, 50B, 50C, 50D, 50E) and at least two functional elements (10), only one functional element (10) is designed to be electrically adjustable by means of the at least one electric motor (52) or at least one functional element (10) is designed to be electrically adjustable by means of the at least one electric motor (52). [7] Gripping device (36) according to one of the preceding claims, characterized by that the bearing element (12) is reversibly pivotable at an angle of up to 15 ° in at least two opposite directions relative to a rest position that can be defined by a user. [8] Gripping device (36) according to one of the preceding claims, characterized byin that the at least one adjustable axis (46, 50A, 50B, 50C, 50D, 50E) is reversibly angularly adjustable in at least two directions relative to a rest position definable by a user, wherein the two directions are oriented at right angles to one another.

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