Gripper unit, system having a gripper unit and use of a gripper unit

Abstract

The invention relates to a gripper unit for handling flat workpieces with different properties, comprising a rectangular carrier structure (5) with two long sides and two short sides, also comprising a plurality of first vacuum suction cups configured in the form of bellows suction cups (2), and further comprising at least two second vacuum suction cups arranged on the carrier structure (5), wherein the bellows suction cups (2) are arranged on the long sides and the short sides of the carrier structure (5) and surround the second vacuum suction cups, and wherein the gripper unit (1) has a floating suction cup (5) arranged in a centre of the carrier structure (5). The invention also relates to a system having a gripper unit, to the use of a gripper unit for handling different flat workpieces, in particular for building a stack comprising a plurality of layers with different properties, and to a method for building a stack of flat workpieces by means of a gripper unit.

Description

[0001] Gripper unit, system with a gripper unit and use of a gripper unit

[0002] FIELD OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a gripper unit for handling flat workpieces with different properties, a system with a gripper unit, and a use of a gripper unit for handling different flat workpieces, in particular for building a stack comprising multiple layers with different properties. The invention further relates to a method for building a stack of flat workpieces with different properties using a gripper unit.

[0004] Gripper units are known for a wide variety of applications. The gripper units are typically attached to the end effector of a manipulator and positioned by the manipulator. The gripper unit is operated by a control system, whereby, depending on the application, a control system of the manipulator or a separate control system is used.

[0005] In the context of this application, a flat workpiece refers to a product or reactant that has a small thickness relative to its surface area. The "flat workpiece" may be, for example, a metal plate, a metal mesh, a plastic mesh, a film, a textile fabric, or the like. Flat workpieces with different properties may differ, for example, but not exclusively, in porosity, surface roughness, inherent stability or flexibility, sensitivity, and / or weight.

[0006] For handling flat workpieces, gripper units are particularly known in which a suction force is applied to grip the workpiece.

[0007] From EP 3 566 984 A1 a handling system is known comprising a vacuum generator and a gripper unit attached to an end effector, wherein the gripper unit is configured to be actuated by a control system to grip an object, wherein the gripper unit comprises at least one flexible suction cup and at least one rigid gripper, wherein the at least one flexible suction cup and the at least one rigid gripper are in fluid communication with the vacuum generator, and wherein each of the at least one flexible suction cup and the at least one rigid gripper is configured to grip a surface of an object by means of vacuum suction force, wherein the vacuum suction force is selectively generated to grip the object in a first material handling operation by the at least one flexible suction cup; in a second material handling operation by the at least one rigid gripper;and in a third material handling operation, to be gripped by the at least one flexible suction cup and the at least one rigid gripper. The gripper unit known from EP 3 566 984 A1 comprises, in one embodiment, an octagonal base plate, in the center of which the rigid gripper is arranged, with four flexible suction cups arranged evenly around the rigid gripper. In another embodiment, a rectangular base plate is provided, which can be divided into two squares, in the centers of which a rigid gripper is arranged, with a total of six flexible suction cups being arranged at the four corners of the base plate and in the center of a long side of the base plate.

[0008] TASK AND SOLUTION

[0009] It is an object of the invention to provide a gripper unit suitable for handling flat workpieces that differ in their properties, wherein the gripper unit enables, in particular, handling of different layers of an electrolyzer cell. Further objects of the invention are to provide a system comprising such a gripper unit, a use of such a gripper unit, and a method for constructing a stack.

[0010] These objects are achieved by the subject matter having the features of claims 1, 10, 11 and 13. Further advantageous embodiments emerge from the subclaims.

[0011] According to a first aspect, a gripper unit for handling flat workpieces with different properties is provided, which comprises a rectangular support structure with two long sides and two short sides, first vacuum suction cups designed as bellows suction cups, at least two second vacuum suction cups arranged on the support structure and a floating suction cup arranged in a center of the support structure, wherein the bellows suction cups are arranged on the long sides and the short sides of the support structure and surround the second vacuum suction cups and the floating suction cup.

[0012] In the context of this application, the terms "a" or "an" are used merely as an indefinite article and not as a number. Likewise, the terms "first," "second," etc., serve merely to distinguish and do not indicate any ranking or order. The gripper unit has three types of vacuum cups: first vacuum cups designed as bellows cups, at least two second vacuum cups, and at least one third vacuum cup designed as a floating vacuum cup.

[0013] In the context of the application, vacuum suction devices are units for applying suction force.

[0014] In one embodiment, the vacuum suction cups are or can be fluidly connected to a negative pressure source, such as a vacuum generator, for generating a suction force at an opening, wherein a workpiece to be gripped is sucked to the opening.

[0015] In the context of this application, bellows suction cups are vacuum suction cups that can be fluidly connected to a vacuum source and comprise one or more bellows, with which the bellows suction cups are placed in a sealing manner on a workpiece. In some embodiments, the bellows has a round cross-section. In other embodiments, bellows with different cross-sections, for example, with oval cross-sections, are provided. The bellows is elastically deformable and allows the bellows suction cup to be placed gently on a workpiece to be picked up, as well as to compensate for unevenness on the surface of the workpiece to be picked up. When the bellows is placed in a sealing manner on a workpiece, the application of a negative pressure inside the bellows causes the bellows to contract.This allows, for example, a layer to be released from the stack when picking up a flat workpiece from a stack. In some embodiments, all bellows suction cups of the gripper unit are of identical design. However, embodiments are also conceivable in which bellows suction cups are used that differ in their size, shape, and / or bellows design.

[0016] In the context of the application, suspended suction cups are referred to as units for applying suction force that operate according to the Bernoulli principle. During operation, a suspended suction cup uses a compressed gas flowing from a central outlet to create a vacuum to lift a workpiece based on the Bernoulli principle. This creates an air cushion between the workpiece and the suspended suction cup, enabling particularly gentle handling of products. A suspended suction cup also allows for the handling of porous workpieces thanks to a high volume flow.

[0017] Depending on the workpiece to be handled, all or some of the bellows suction cups, both or a second vacuum suction cup, and / or the floating suction cup are activated. The bellows suction cups, arranged along the long and short sides, allow for gripping unstable workpieces with low inherent stability.

[0018] The floating vacuum cleaner allows, in particular, the handling of air-permeable layers of a fuel cell or electrolyzer, such as so-called gas diffusion layers (GDL). Furthermore, the floating vacuum cleaner allows the handling of membranes, in particular catalyst-coated membranes (CCMs), such as those used in electrolyzers or fuel cells.

[0019] The second vacuum suction cups are designed as ejectors with a suction nozzle, an air outlet connected to the suction nozzle via a suction channel and a compressed air connection opening into the channel.

[0020] In the context of this application, ejectors refer to units for applying suction force, in which compressed air is introduced into a suction channel connected to a suction nozzle, thereby generating a suction force at the suction nozzle. The compressed air generates a high suction force, allowing even flat workpieces with high air permeability, such as grid structures, to be handled by the gripper unit. In particular, the ejectors allow for the secure gripping of metal sheets for use in an electrolyzer, which have open grid-like structures.

[0021] In one embodiment, the at least two second vacuum suction cups are spaced apart from one another along the long side of the support structure and arranged on opposite sides of the suspended suction cup. This arrangement has proven particularly advantageous for applying different suction forces for handling different flat workpieces. In advantageous embodiments, the second vacuum suction cups are arranged symmetrically with respect to the center axes of the support structure. A symmetrical arrangement is particularly advantageous for handling equally symmetrical workpieces.

[0022] In one embodiment, the support structure is a plate. In advantageous embodiments, the support structure is designed as a frame, comprising struts arranged on the long sides and the short sides, wherein the bellows suction cups are attached to the struts. By designing the support structure as a frame, free spaces are created on the support structure which can be used by sensors attached to the gripper unit and / or a manipulator receiving the gripper unit. In addition, designing the support structure as a frame allows a weight reduction compared to a solid design. In one embodiment, lines are provided on the struts, by means of which lines the bellows suction cups attached to the struts are fluidically connected to a vacuum source. In advantageous embodiments, the struts have connections and channel structures for a fluidic connection of the bellows suction cups to a vacuum source.

[0023] In some embodiments, the struts are connected to one another at the corners. In advantageous embodiments, the struts are shorter than the long sides and / or the short sides of the support structure, so that a free space remains between adjacent struts at corners of the support structure. The free spaces expose corners of a picked up or to be picked up flat workpiece, so that these corners can be used by sensors to determine the position of the gripper unit relative to the flat workpiece. Alternatively or additionally, the free space can be used by sensors, which can be used to detect the distance between the gripper unit and a workpiece to be picked up and / or whether a workpiece has been picked up. Depending on the embodiment, the sensors are attached to the gripper unit and / or a manipulator that picks up the gripper unit.

[0024] The support structure is designed in two parts, comprising two mirror-image, identical frame parts. This two-part design is advantageous from a manufacturing perspective.

[0025] In some embodiments, the frame comprises two webs, each connected to at least one strut, wherein the second vacuum suction cups are each attached to a web.

[0026] In one embodiment, the gripper unit further comprises sensors which are attached to the support structure.

[0027] According to a second aspect, a system comprising a gripper unit with first vacuum suction cups designed as bellows suction cups, second vacuum suction cups, in particular designed as ejectors, and a third vacuum suction cup designed as a levitating suction cup, and a control device is provided, wherein the first vacuum suction cups, the second vacuum suction cups, and / or the third vacuum suction cup can be activated individually or in groups for handling different flat workpieces by means of the control device. In one embodiment, the system also comprises one or more system-internal vacuum sources and / or one or more system-internal compressed air sources for operating the vacuum suction cups. In other embodiments, the system additionally or alternatively uses vacuum sources and / or compressed air sources that are present in a periphery of the system.According to a third aspect, a gripper unit with first vacuum suction cups designed as bellows suction cups, second vacuum suction cups, in particular designed as ejectors, and a third vacuum suction cup designed as a floating suction cup is provided for handling different flat workpieces to build a stack. For handling different flat workpieces, the first vacuum suction cups, the second vacuum suction cups, and / or the third vacuum suction cup can be selectively activated individually or in groups. Depending on the application, it is provided that all of the first vacuum suction cups or only some of the first vacuum suction cups are / are activated to grip a workpiece.

[0028] In particular, in one embodiment, a use of a gripper unit with first vacuum suction cups designed as bellows suction cups, second vacuum suction cups designed in particular as ejectors and a third vacuum suction cup designed as a floating suction cup for handling different flat workpieces for the complete or partial construction of a cell of an electrolyzer comprising several layers is provided, wherein the bellows suction cups, the second vacuum suction cups and / or the floating suction cup can be selectively activated individually or in groups for handling different layers.

[0029] According to a fourth aspect, a method is provided for building a stack of flat workpieces with different properties by means of a gripper unit, wherein the bellows suction cups, the second vacuum suction cups and / or the floating suction cup are selectively activated individually or in groups for handling different flat workpieces.

[0030] In particular, in one embodiment, a method is provided for the complete or partial construction of a cell of an electrolyzer comprising a plurality of layers, wherein the bellows suction cups, the second vacuum suction cups and / or the floating suction cup are selectively activated individually or in groups for handling different layers of the cell.

[0031] BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantages and aspects of the invention will become apparent from the claims and the following description of an embodiment of the invention, which is explained with reference to the figures. In the figures:

[0033] Fig. 1 shows an embodiment of a gripper unit in a perspective view;

[0034] Fig. 2 shows the gripper unit according to Fig. 2 in a perspective bottom view; and Fig. 3 shows schematic layers of a cell of an electrolyzer.

[0035] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Figs. 1 and 2 show a gripper unit 1 that allows handling of a variety of different flat workpieces (not shown in Figs. 1 and 2). The gripper unit 1 is particularly suitable for use in a stack structure consisting of multiple layers with different properties. For example, the gripper unit is suitable for use in an electrolyzer structure comprising one or more cells, wherein all or at least several different layers are handled by the gripper unit 1.

[0037] Fig. 3 schematically shows a base plate 100 on which one or more cells 200 of an electrolyzer are mounted. In the illustrated embodiment, a cell 200 comprises nine layers 201, ..., 209.

[0038] The layers 201, ..., 209 of the cell 200 differ in terms of their shape, size and weight as well as in terms of their surface properties, their inherent stability and / or their porosity or air permeability.

[0039] The gripper unit 1 shown in Figs. 1 and 2 allows handling, ie gripping, holding during transport and depositing of all layers 201, ..., 209 of the cells 200 according to Fig. 3. However, the layers 201, ..., 209 shown are merely exemplary and the invention is not limited to the handling of these layers shown in Fig. 3.

[0040] The gripper unit 1 shown in Figs. 1 and 2 comprises several different vacuum suction cups for handling various flat workpieces. In the illustrated embodiment, the gripper unit comprises sixteen bellows suction cups 2, two ejectors 3, and one floating suction cup 4.

[0041] The bellows suction cups 2, the ejectors 3 and the floating suction cup 4 are attached to a rectangular support structure 5.

[0042] The illustrated support structure 5 is designed as a frame. The illustrated frame comprises two identical frame parts 50, which are arranged in a mirror image of each other. In other embodiments, a one-piece frame structure is provided. The floating suction device 4 is mounted centrally on the support structure 5 and connected to both frame parts 50.

[0043] The frame comprises struts 52, 53, which are arranged on the long sides and short sides of the support structure 5, respectively. The bellows suction cups 2 are attached to the struts 52, 53. In the illustrated embodiment, the struts 52, 53 are each shorter than the long sides and the short sides of the support structure 5, so that a free space remains between adjacent struts 52, 53 at corners of the support structure 5. A bellows suction cup 2 is attached to each of the mutually facing free ends of the struts 52, 53. Further bellows suction cups 2 are attached to the struts 53 arranged on the long sides. In the illustrated embodiment with two frame parts 50, two aligned struts 52 are provided on each long side, with two further bellows suction cups 2 being arranged on each strut 52.

[0044] The struts 52, 53 have connections 54 visible in Fig. 1 and channel structures not visible in the figures for a fluidic connection of the bellows suction cups 2 with a vacuum source not shown.

[0045] At the free ends of the bellows suction cups 2, a bellows 20 is provided, by means of which the bellows suction cups 2 are placed on a workpiece to be picked up (not shown).

[0046] The two ejectors 3 are spaced apart from each other in the direction of the long side of the support structure 5 and arranged on opposite sides of the suspended suction device 4. In the illustrated embodiment, the ejectors 3 are arranged symmetrically with respect to the central axes 51 (see Fig. 2) of the support structure 5.

[0047] In the illustrated embodiment, the ejectors 3 are each attached to a web 55 spanning an interior space of a frame part 50. In the illustrated embodiment, the webs 55 are each connected to a strut 53 arranged on the short sides and to a transverse strut 56 parallel thereto.

[0048] The ejectors 3 have a suction nozzle 30 facing the workpieces to be picked up (not shown), an air outlet 31 connected to the suction nozzle 30 via a channel, and a compressed air connection 32 for supplying compressed air to the channel. A compressed air supply to the channel creates a suction force at the suction nozzle 30. Lines (not shown in some embodiments) for discharging the supplied air are arranged at the air outlet 31, for example, for use in a clean room. The suspended vacuum cleaner 4 has a compressed air connection 40 (see Fig. 1) for connection to a compressed air supply (not shown). A central outlet opening 41 is provided on an opposite side of the suspended vacuum cleaner 4 facing the workpieces, wherein supplied compressed air is blown out in the radial direction of the suspended vacuum cleaner 4.

[0049] For use, the gripper unit 1 is coupled to a control device (not shown), so that by means of the control device the bellows suction cups 2, the ejectors 3 and / or the floating suction cup 4 can be activated individually or in groups for handling different flat workpieces.

[0050] In the illustrated embodiment, the bellows suction cups 2 can be connected to a vacuum source (not shown) via a plurality of connections 54. Depending on the application, it is also possible to selectively activate only a subset of the bellows suction cups 2. For this purpose, in one embodiment, several identical or differently designed vacuum sources are provided. In other embodiments, all bellows suction cups 2 can be fluidically connected to a common vacuum source.

[0051] In some embodiments, the ejectors 3 and the floating suction device 4 use a common compressed air source or, in other embodiments, are fluidically connected to several compressed air sources.

[0052] The gripper unit 1 is mounted on a manipulator (not shown) for use in advantageous applications. In the illustrated embodiment, a connecting plate 57 is provided on each of the frame parts 50 for this purpose. The connecting plate 57 is arranged at a distance from the struts 52, 53 in a direction perpendicular to the support structure 5. By means of the manipulator, the gripper unit 1 can be positioned relative to a workpiece to be picked up for receiving the workpiece, and can be moved with the workpiece for handling the workpiece.

[0053] For safe handling, sensors are arranged on an end effector of the manipulator and / or on the gripper unit 1 in some embodiments, by means of which, for example, a distance to a workpiece to be picked up, a presence of a workpiece or other states can be detected.

[0054] In the illustrated embodiment, the struts 52, 53 of the support structure 5 are shorter than the long sides and / or the short sides of the support structure 5, so that a free space remains between the struts 52, 53 at each corner of the support structure 5. This free space can be used by sensors (not shown) to detect the reliable detachment of a workpiece, in particular a layer for a cell of an electrolyzer, from a supply arranged as a stack. This free space can also be used by sensors to detect the position of a layer to be picked up or a layer that has been picked up relative to the gripper unit. Depending on the design, the sensors are sensors arranged on the gripper unit and / or sensors of a peripheral camera or measuring system.

Claims

Claims 1. Gripper unit for handling flat workpieces with different properties, comprising a rectangular support structure (5) with two long sides and two short sides, a plurality of first vacuum suction cups designed as bellows suction cups (2) and at least two second vacuum suction cups arranged on the support structure (5), wherein the bellows suction cups (2) are arranged on the long sides and the short sides of the support structure (5) and surround the second vacuum suction cups, characterized in that the gripper unit (1) has a floating suction cup (5) arranged in a center of the support structure (5).

2. Gripper unit according to claim 1, characterized in that the second vacuum suction cups are designed as ejectors (3) with a suction nozzle (30), an air outlet (31) connected to the suction nozzle via a suction channel and a compressed air connection (32) opening into the channel.

3. Gripper unit according to claim 1 or 2, characterized in that the at least two second vacuum suction cups are arranged at a distance from one another in the direction of the long side of the support structure (5), on opposite sides of the floating suction cup (5), wherein the second vacuum suction cups are preferably arranged symmetrically with respect to central axes (51) of the support structure (5).

4. Gripper unit according to claim 1, 2 or 3, characterized in that the support structure (5) is designed as a frame, comprising struts (52, 53) arranged on the long sides and the short sides, wherein the bellows suction cups (2) are attached to the struts (52, 53).

5. Gripper unit according to claim 4, characterized in that the struts (52, 53) have connections (54) and channel structures for a fluidic connection of the bellows suction cups (2) to a vacuum source.

6. Gripper unit according to claim 4 or 5, characterized in that the struts (52, 53) are shorter than the long sides and / or the short sides of the support structure (5), so that a free space remains between adjacent struts (52, 53) at corners of the support structure (5).

7. Gripper unit according to claim 4, 5 or 6, characterized in that the support structure (5) is designed in two parts, comprising two mirror-inverted, identical frame parts (50).

8. Gripper unit according to one of claims 4 to 7, characterized in that the frame has two webs (55), each connected to at least one strut (53), wherein the second vacuum suction cups are each attached to a web (55).

9. Gripper unit according to one of claims 1 to 8, characterized in that sensors are attached to the support structure.

10. System comprising a gripper unit (1) according to one of claims 1 to 9 and a control device, wherein by means of the control device the bellows suction cups (2), the second vacuum suction cups (3) and / or the floating suction cup (4) can be activated individually or in groups for handling different flat workpieces.

11. Use of a gripper unit (1) according to one of claims 1 to 9 for handling different flat workpieces to build up a stack, wherein the bellows suction cups (2), the second vacuum suction cups (3) and / or the floating suction cup (4) can be selectively activated individually or in groups for handling different flat workpieces.

12. Use according to claim 11 for the complete or partial construction of a cell of an electrolyzer comprising several layers, wherein the bellows suction cups (2), the second vacuum suction cups (3) and / or the floating suction cup (4) can be selectively activated individually or in groups for handling different layers.

13. Method for building a stack of flat workpieces with different properties by means of a gripper unit according to one of claims 1 to 9, wherein for handling different flat workpieces the bellows suction cups (2), the second vacuum suction cups (3) and / or the floating suction cup (4) are selectively activated individually or in groups.

14. Method according to claim 13 for the complete or partial construction of a cell of an electrolyzer comprising several layers, wherein for handling different layers the bellows suction cups (2), the second vacuum suction cups (3) and / or the floating suction cup (4) are selectively activated individually or in groups.

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