Transport device and method for lifting flat objects

Abstract

The invention relates to a handling device (1) for separating flat objects (4) of a first type and flat objects (5) of a second type, which are arranged in an alternating stack and are not completely overlapped, the invention relates to a device for clamping flat objects (4, 5) of a first type, comprising at least one main clamp (7) for clamping one of the flat objects (4) of the first type and at least one auxiliary clamp (12) for additionally clamping one of the flat objects (5) of the second type, the different clamps (7, 12) being fixed on a common support structure (6, 8) and being displaceable relative to each other in the vertical direction, according to the invention, the different flat objects (4, 5) are arranged such that when the different flat objects (4, 5) are lifted, an increased distance can be produced between these objects (4, 5).

Description

Summary of the Invention

[0001] The present invention relates to a handling device suitable for separating flat objects of different types stacked on top of one another, wherein objects of a first type and objects of a second type are arranged alternately in a stack. Furthermore, the present invention relates to a method for lifting such stacks of flat objects having an alternating layer sequence. Background Art

[0002] EP 4 002 533 A1 discloses a device and a method for stacking fuel cell assemblies. The patent assumes that the cell assemblies for manufacturing fuel cells are delivered individually. The cell assemblies are fed into a vertical stacker in an individual arrangement (i.e., arranged at intervals from one another). The vertical stacker comprises a vertical hopper that enables the cell assemblies contained therein to be moved up and down. The vertical stacker is designed to distribute the cell assemblies individually by means of a vertical downward movement. In general, the device according to EP 4 002 533 A1 is designed for the large-scale production of fuel cells.

[0003] A vacuum gripper with multiple suction points is known from DE 20 2006 021 243 U1. In this patent, the suction points communicate with a control unit of the vacuum gripping system. Each suction point has a sensor and a valve, with the sensor being located in the low-pressure line. According to DE 20 2006 021 243 U1, each suction point is equipped with its own low-pressure generator.

[0004] DE 10 2007 025 098 A1 describes a control device for contactlessly separating, centering, gripping, and handling flat, disc-shaped objects. Part of the device is a compressed air supply, which separates stacked flat, disc-shaped objects by impacting the stack with a timed stream of compressed air. The device according to DE 10 2007 025 098 A1 can also be used to handle semiconductor wafers and solar cells.

[0005] Other devices for handling objects, in particular those having a flat shape, are known from the documents DE 10 2012 200 535 A1, DE 10 2017 107 215 A1, DE 10 2013 201 247 B4 and DE 10 2015 119 321 A1. Summary of the Invention

[0007] The object of the present invention is to further develop the handling of flat modules, in particular modules suitable for assembling fuel cell stacks, compared to the prior art, so that a particularly favorable ratio between equipment costs and process reliability is achieved.

[0008] According to the invention, this object is achieved by a handling device having the features of claim 1. This object is also achieved by a method for lifting flat objects from a stack according to claim 10. The configurations and advantages of the invention explained in the following also apply to a handling device configured as a sorting device, and vice versa.

[0009] Suppose there is a stack consisting of flat objects of a first type and flat objects of a second type, in which the different objects are stacked alternately on top of each other. In this case, the first type objects do not completely cover the second type objects below them. This means that the different objects are not arranged completely overlapping in the stack. The difference from a completely overlapping arrangement can be seen in particular by the fact that the first type objects have an arrangement grid so that when the first type objects are the top layer of the entire stack, the arrangement grid, that is, the size of the cross-section of the second type objects, can be seen from above. Alternatively, the second type objects located at the bottom can extend laterally beyond the first type objects. In any case, the design and arrangement of the different objects makes it possible to lift them simultaneously, in particular by means of low pressure.

[0010] To achieve this purpose, the handling device comprises at least one main clamp and at least one auxiliary clamp. The main clamp is used to lift a first type of flat object. For example, the main clamp is designed as a vacuum clamp for adsorbing the first type of flat object. Alternatively, the main clamp can be based on any other physical principle. For example, the main clamp can be an adhesive clamp, a pneumatic clamp, or a magnetic clamp. Similarly, the auxiliary clamp can be a vacuum clamp or other clamp suitable for lifting flat objects.

[0011] When referring to a main vacuum gripper or an auxiliary vacuum gripper below, the corresponding statements apply similarly to the other types of main grippers or auxiliary grippers. While the main gripper is lifting a flat object of a first type, at least one auxiliary gripper (particularly an auxiliary vacuum gripper) is always capable of lifting a flat object of a second type located below it. Typically, the weight per unit surface area of ​​the second type of object is less than the weight per unit surface area of ​​the first type of object.

[0012] The different grippers, in particular vacuum grippers, are fastened to a common support structure and can be moved vertically relative to one another, so that an increased distance can be generated between the different flat objects when they are lifted.

[0013] Optionally, the auxiliary vacuum clamp is connected to one or more air outlets for introducing airflow between the different flat objects. Blowing air into the gap created by the two flat objects being lifted helps to continuously separate the lower flat object from the upper flat object. The air outlets provided for this purpose are, for example, located on a vertical tube, the lower end of which the auxiliary vacuum clamp is fixed to.

[0014] According to one possible embodiment, the auxiliary clamp (in particular in the form of an auxiliary vacuum clamp) is mounted in an elastically supported manner relative to the main vacuum clamp or other main clamps, so that the vertical distance between the different clamps is maximized, that is, the above-mentioned gap space is enlarged. This also applies to the case where the handling device has a plurality of auxiliary vacuum clamps, for example, two auxiliary vacuum clamps that are smaller than the main clamp and are arranged on relatively radially opposite sides adjacent to the main clamp. For example, a compression spring in the form of a coil spring is suitable for the elastic support device. In addition to using a compression spring to apply force to the auxiliary vacuum clamp, a tension spring acting on the main clamp can also be used. In any case, the final repulsive force of the second type of flat object located below can be supported by the downward air flow emitted by the auxiliary vacuum clamp.

[0015] According to a possible further development, a container is provided with a shearing plate which is inserted into the intermediate space formed between the different flat objects and, when pushing the flat objects, separates the lower of the two flat objects from the auxiliary vacuum gripper. The mechanical action of the shearing plate, i.e., the feeding of the flat objects released by the auxiliary vacuum gripper into the container, can optionally be supplemented by a blower (i.e., a suction device) located in or connected to the container.

[0016] The handling device is particularly suitable for lifting stacked fuel cell assemblies. The first type of flat objects can be bipolar plates or membrane electrode assemblies. In this case, the second type of objects can be intermediate layers to be handled.

[0017] The method for lifting flat objects of different types in the form of a stack, if the objects stacked alternately in the stack are arranged in such a way that each flat object of a first type does not completely cover the underlying flat object of a second type, generally comprises the following steps:

[0018] - contacting a flat object of a first type with a primary gripper (e.g. a vacuum gripper or a pneumatic gripper) and simultaneously contacting a flat object of a second type with at least one auxiliary gripper,

[0019] The auxiliary clamp can also be designed as a vacuum clamp or a pneumatic clamp,

[0020] - remove the main fixture together with the flat objects of the first type from the auxiliary fixture and the second type

[0021] Move vertically apart in an arrangement of objects of the same type;

[0022] - Blast air into the gaps formed between the different flat objects, thereby

[0023] The flat object is removed from at least one auxiliary fixture;

[0024] - The auxiliary grippers release the flat objects of the second type while continuing to convey the flat objects of the first type held by the main grippers.

[0025] The second type of flat objects typically refers to a layer made of a flexible material. The first type of flat objects can be made of either flexible or rigid materials. The release of the flexible layer and the transfer of the first type of upper layer objects to an assembly device independent of the handling device can be performed at high frequency, with a time as short as less than one second. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] An embodiment of the present invention is described in detail below with reference to the accompanying drawings. The schematic diagram is as follows:

[0027] Figure 1 A handling device for lifting various flat objects from a stack is shown.

[0028] Figure 2 A handling device is shown which comprises a container for receiving a layer of a stack of flat objects to be processed.

[0029] Figure 3 Shows the basis Figure 2 A top view of the component arrangement. DETAILED DESCRIPTION

[0030] The handling device, generally designated by reference numeral 1, comprises a gripping device 2 used when assembling a fuel cell stack. The gripping device 2 is designed to lift flat objects 4, 5 from an arrangement of flat plates 3 (often referred to as a stack). In the stack 3, different objects 4, 5 are stacked alternately. A maximum of one pair of objects 4, 5 is shown in the figure.

[0031] The clamping device 2 includes a vertically adjustable central support 6, from which a crossbeam 8 extends. The central support 6 and the crossbeam 8 are components of a supporting structure. The main clamp 7 is suspended from the central support 6. In the above case, the main clamp 7 is a pneumatic clamp. Alternatively, the main clamp 7 can also be designed as a vacuum clamp, for example. In addition, two clamping devices are connected to the central support 6 via the crossbeam 8, which are collectively referred to as side clamps 9 and 10, which are respectively arranged on relatively radially opposite sides adjacent to the main clamp 7. Each side clamp 9, 10 is equipped with a vertical tube 11, which is spaced parallel to the central support 6. Figure 1In the arrangement shown, the vertical tube 11 at the rear is not visible in this figure. The auxiliary clamp 12 (designed as a vacuum clamp in this example) is suspended from the vertical tube 11. The vertical tube 11 can move in its longitudinal direction relative to the central support 6, so that the auxiliary vacuum clamp 12 can move in its vertical direction relative to the main clamp 7. For example, Figure 1 A compressed air fitting 13 is shown connected to the auxiliary vacuum clamp 12. A spring 14 applies vertical downward pressure to the auxiliary vacuum clamp 12.

[0032] An air outlet 15 is provided in the lower region of the vertical tube 11, slightly above the auxiliary vacuum clamp 12. This allows the airflow (LS) to be discharged in a generally horizontal direction. In this embodiment, the auxiliary vacuum clamp 12 is also capable of discharging the airflow (LS) in a vertically downward direction. The air drawn in by the vacuum clamps 7 and 12 is generally referred to as the suction air (AL).

[0033] As long as the flat arrangement 3 has not yet been processed, the different flat objects 4, 5 are stacked directly together. Figures 1 to 3 In the arrangement, the top object 4, often also referred to as the main plate or upper layer, is a bipolar plate in this embodiment, which is assembled with other components to form a fuel cell stack. Similarly, the main plate 4 can be a membrane electrode assembly, which is also used to construct a fuel cell stack. Unlike the upper layer 4, the second type of flat object 5, also known as the middle layer, serves only to separate the main plates 4 from each other in the flat plate arrangement 3 and is not intended to construct a fuel cell stack. As shown in the figure, the middle layer 5 is significantly thinner than the upper layer 4. In addition, the middle layer 5 is significantly more flexible than the main plate 4.

[0034] When lifting the main plate 4 from the flat plate array 3, care must be taken to ensure that the intermediate layer 5 is securely removed before installing the main plate 4 in the fuel cell stack. First, the various flat objects 4 and 5 are selectively lifted together from the flat plate array 3. When the clamping device 2 is placed on the flat plate array 3, the auxiliary vacuum clamps 12 contact the recessed areas in the main plate 4, allowing them to directly contact and lift the intermediate layer 5. Simultaneously, the main clamps 7 contact the surface areas of the main plate 4 that are free of recesses.

[0035] From this state, the main plate 4 and the intermediate layer 5 are attracted to the clamping device 2 by the negative pressure, and the central support 6 is lifted together with the main clamp 7, thereby forming Figure 1 The vertical tube 11 including the auxiliary vacuum clamp 12 is pressed downward by the spring 14, thereby separating the middle layer 5 from the main board 4. Figure 1 As shown, the air outlet 15 is located in the gap formed between the different flat objects 4, 5. In order to separate the intermediate layer 5 from the auxiliary vacuum clamp 12, compressed air is exhausted from the air outlet 15 and the auxiliary vacuum clamp 12.

[0036] Figure 2 and Figure 3 The container 16 visible in the figure can be used for processing the intermediate layer 5. The container wall is marked with 17. In addition to the wall 17, the upper area of ​​the container 16 is also provided with a shear plate 18. Figure 2 and Figure 3 As shown, when two flat objects 4, 5 are moved in the conveying direction (FR), shears 18 are inserted into the gap between the different objects 4, 5. Thus, shears 18 peel off the intermediate layer 5, provided that the intermediate layer 5 does not fall into the container 16 on its own. In this embodiment, a suction device 19 assists in feeding the intermediate layer 5 into the container 16.

[0037] List of Reference Numerals

[0038] 1. Transport device

[0039] 2 Clamping device

[0040] 3 flat plate arrangement, stacking

[0041] 4. First type of flat objects, main board, upper layer

[0042] 5. Second type of flat objects, middle layer

[0043] 6 Center bracket

[0044] 7 Main fixture

[0045] 8 beam

[0046] 9 side clamps

[0047] 10 side clamps

[0048] 11 vertical tube

[0049] 12 Auxiliary fixture

[0050] 13 Compressed air connector

[0051] 14 Spring

[0052] 15 air outlet

[0053] 16 containers

[0054] 17 container wall

[0055] 18 Shearing

[0056] 19 Suction device

[0057] AL Inhaled air

[0058] FR conveying direction

[0059] LS airflow

Claims

1. A handling device (1) for separating alternately stacked, incompletely overlapping flat objects of a first type (4) and flat objects of a second type (5), comprising at least one main clamp (7) for clamping one of the flat objects of the first type (4) and at least one auxiliary clamp (12) for additionally clamping one of the flat objects of the second type (5), wherein the different clamps (7, 12) are fixed to a common support structure (6, 8) and can be displaced relative to each other in the vertical direction so that an increased distance can be generated between the different flat objects (4, 5) when they are lifted.

2. The handling device (1) according to claim 1, characterized in that The auxiliary clamp (12) is mounted in an elastically supported manner relative to the main clamp (7), so that the vertical distance between the different clamps (7, 12) is maximized.

3. The handling device (1) according to claim 1 or 2, characterized in that The auxiliary fixture (12) is provided with an air outlet (15), and the air outlet (15) is used to introduce air flow between the different flat objects (4, 5).

4. The handling device (1) according to any one of claims 1 to 3, characterized in that At least two auxiliary clamps (12) are arranged on opposite radial sides immediately adjacent to the main clamp (7).

5. The handling device (1) according to claim 4, characterized in that The auxiliary clamp (12) is smaller than the main clamp (7).

6. The handling device (1) according to any one of claims 3 to 5, characterized in that The at least one auxiliary fixture (12) is also designed to discharge a downwardly directed air flow.

7. The handling device (1) according to any one of claims 1 to 6, characterized in that A container (16) having a shearing plate (18) designed to be inserted into the intermediate space formed between the different flat objects (4, 5) and to separate the lower one (5) of the two flat objects from the auxiliary clamp (12) when the flat objects (4, 5) are pushed.

8. Use of the handling device (1) according to claim 1 for lifting fuel cell assemblies (4) stacked on top of each other.

9. The use according to claim 8, characterized in that The handling device (1) is used to separate fuel cell assemblies (4), wherein the fuel cell assemblies (4) are selected from a group of assemblies including bipolar plates and membrane electrode assemblies and are required to be lifted by the main clamp (7), while the flat object (5) lifted by the auxiliary clamp (12) is not an intermediate layer for installation in a fuel cell stack.

10. A method for lifting flat objects (4, 5) of different types in stack form, comprising the following steps: - providing a stack of flat objects (4, 5), wherein the flat objects (4) of the first type do not completely cover the flat objects (5) of the second type; - contacting the flat objects (4) of the first type with a main gripper (7) and simultaneously contacting the flat objects (5) of the second type with at least one auxiliary gripper (12); - vertically moving the main clamp (7) together with the flat objects (4) of the first type away from the arrangement of the auxiliary clamp (12) and the objects (5) of the second type; - introducing blast air into the gap formed between the different types of flat objects (4, 5); - continuing to convey the flat object (4) of the first type gripped at the main gripper (7) while the auxiliary gripper (12) releases the object (5) of the second type.

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