Suction cup for a handling device

Abstract

The invention relates to a suction cup (1; 101) for a handling device, comprising a suction cup (2) which is provided with a vacuum connection (14) on a cup base (11) and which is connected to an intermediate ring (3; 103) at a cup mouth (13), wherein the intermediate ring (3; 103) is provided with a carrier ring (4; 104) on an axial end region facing away from the suction cup (2), and wherein the carrier ring (4; 104) is provided with a sealing ring (5; 105) on an axial end region facing away from the intermediate ring (3; 103), which sealing ring is designed for a sealing engagement with an object to be handled.

Description

The invention relates to a suction cup for a handling device.DE 40 40 570 A1 discloses a seal for sealing the suction gripper on the surface of the object to be engaged consists of soft-elastic, preferably open-cell foam, wherein the plate-shaped seal covers the entire open side of the suction gripper to be placed on the surface of the object and a stop is formed by a perforated plate or a wire mesh, wherein a perforated plate or a wire mesh forms a stop for the central part of the plate-shaped seal, which partially escapes into its cavity when the suction gripper is suctioned fast, so that the suction gripper can engage well on less planar and less smooth surfaces and can pick up objects of different surface configurations.DE 10 2013 009 344 A1 discloses a suction gripper for holding flexible articles by means of negative pressure, wherein the suction gripper has a suction recess which has a working opening on a front side and which is divided by an air-permeable suction wall from a suction chamber which can be acted upon by negative pressure, and wherein the suction wall is penetrated by a multiplicity of suction ducts which open out with suction openings at a suction surface of the suction wall facing the suction recess, and wherein the suction surface is shaped concave, such that the suction openings are arranged in a three-dimensional distribution around the suction recess.DE 198 17 323 A1 discloses a suction gripper with a kinematic joint, the production of which is cost-effective and with which already present suction grippers can be retrofitted without special circumstances, wherein the joint has an elastic body, preferably in the form of a rubber disk, which is connected in a rotationally fixed manner both to the suction gripper and to a connecting piece connecting the suction gripper to a lifting deviceThe object of the invention is to provide a suction cup which can be flexibly adapted to different use conditions.This object is achieved for a suction cup of the type mentioned at the beginning with the features of claim 1, wherein the suction cup has a suction cup which is provided on a cup base with a vacuum connection and which is connected at a cup mouth with an intermediate ring, wherein the intermediate ring is provided at an axial end region facing away from the suction cup with a carrier ring and wherein the carrier ring is provided at an axial end region facing away from the intermediate ring with a sealing ring which is designed for sealing contact with a handling object.The suction cup can have a planar or bowl-shaped cup base on which a vacuum connection is formed, which can be configured in a dual function on the one hand for providing a negative pressure to the suction cup and on the other hand as a mechanical interface for coupling to a handling device, for example a hand axle of an industrial robot. The vacuum connection is preferably designed as a substantially circular cylindrical connection piece, through which a fluid bore passes and which can be provided with a thread on an inner surface and / or on an outer surface. Adjoining the cup base in an axial extension direction is a sleeve-shaped cup wall, in particular formed with circular ring-shaped profiling, wherein an end region of the cup wall facing away from the cup base delimits a cup mouth.This cup mouth is provided for connection to an intermediate ring, wherein this connection is preferably formed in a force-fit and / or form-fit manner. The intermediate ring serves as a coupling part between the suction cup and a carrier ring which is in turn fixed to an axial end region of the intermediate ring which is remote from the suction cup. The connection of intermediate ring and carrier ring is preferably formed in a force-fit and / or form-fit manner. On an axial end region of the carrier ring facing away from the intermediate ring, a sealing ring is arranged, which is designed for sealing contact with a handling object.This handling object can be, for example, a workpiece which has to be transported from one machining step to a next machining step. The handling object can also be a food such as, for example, an apple or an orange, which can be gently lifted and deposited with the aid of the suction cup. The handling object can also be a film bag which can be lifted and set down again with the aid of the suction cup without interfering with the film bag from which the film bag is produced.The sealing ring can be advantageously adapted to the respective application provided for the suction cup by the modular construction of the suction cup. For example, a sealing ring which has a low elasticity can be used for handling a film pouch, while a sealing ring which has a high elasticity can be used for handling a food to avoid pressure points.According to the invention, it is provided that a plurality of vacuum channels are formed on an inner surface of the cup base of the suction cup, which vacuum channels are connected in a fluidically communicating manner to a connection bore of the vacuum connection and which are bounded by a plurality of projections arranged at a distance from one another and protruding in the axial direction. The vacuum channels aim for the most homogeneous possible application of negative pressure to the handling object, wherein for this purpose the most uniform possible planar distribution of the vacuum channels over the inner surface of the cup base is to be provided. The vacuum channels are preferably designed to be completely open in the direction of the cup mouth, as a result of which production of the suction cup by the plastic injection molding process is facilitated. The vacuum channels are bounded by projections which are arranged at a distance from one another and project in the axial direction and which can be designed, for example, in the form of cutting edges or in the form of pins. The vacuum channels can either all extend starting from the fluid bore of the vacuum connection or be designed as a multibranched channel arrangement.It is preferably provided that the suction cup has a first interface at a cup mouth and that the intermediate ring is provided at mutually opposite axial end regions with a second interface and with a third interface, wherein the second interface is configured for coupling with the first interface of the suction cup, and that the carrier ring is provided at an axial end region with a fourth interface configured for coupling with the third interface of the intermediate ring. Preferably, the interfaces are each designed for a fluid-tight connection between the suction cup and the intermediate ring or between the intermediate ring and the carrier ring, in order to prevent an ingress of false air into a suction chamber delimited by the suction cup, wherein the suction chamber is to be closed by the handling object abutting the sealing ring during the intended use of the suction cup. In order to be able to ensure these properties for the interfaces, it can be provided, for example, that the interfaces corresponding to one another (first and second interface and third and fourth interface) each have inner and outer surfaces which bear flat against one another and which can be designed in particular in the form of a cylinder jacket or in the form of a conical jacket. By means of a circumferential contact of the interfaces corresponding to one another, with suitable dimensioning, in particular with a geometrically similar embodiment of the interfaces, a sealing effect can thus be achieved without additional sealing means, which is sufficient for many application cases, in particular if handling objects such as food or film bags that are more sensitive are to be lifted and deposited with the suction cup.It is advantageous if the first interface and the second interface and / or that the third interface and the fourth interface are designed as a positive connection from the group: locking connection with a locking groove running around at least in sections and recessed in the radial direction and with a locking protrusion running around at least in sections and protruding in the radial direction, bayonet connection with an axial undercut and a support protrusion designed for axial support on the axial undercut. With regard to the positive-locking effect between the respective interfaces, it is assumed that the positive locking is effective in the direction of a cup axis which extends from the cup bottom in the direction of the cup mouth and, in the case of a rotationally symmetrical configuration of the suction cup, also corresponds to the axis of rotational symmetry.The positive connection can be configured for one or both of the interface combinations (first interface with second interface and third interface with fourth interface) as a latching connection, in which a purely linear movement between suction cup and intermediate ring and / or between carrier ring and intermediate ring is sufficient to bring about the positive connection. In this case, it is provided that a latching groove which runs circumferentially at least in regions and is recessed in the radial direction is formed on in each case one of the two interfaces and into which a latching projection which runs circumferentially at least in regions and extends in the radial direction and is formed on the respective other interface can engage. It is preferably provided that the latching groove and the latching protrusion are formed rotationally symmetrically circumferentially on the respective interface, so that no rotational orientation between the interfaces to be connected is to be observed.In one embodiment of the positive connection as a bayonet connection for one or both of the interface pairings, a predefined movement sequence must be observed between the two interfaces in order to achieve the desired coupling of the interfaces to be connected. It is preferably provided that for the coupling process, first a linear approach movement is carried out between the two interfaces along the cup axis until a mechanical overlap of the two interfaces is present, in order subsequently to achieve the desired coupling by a rotational relative movement between the two interfaces about the cup axis. For this coupling, one of the two interfaces has an axial undercut which has a surface normal which is oriented at least substantially parallel to the cup axis. The respective other interface has a supporting projection which is designed to bear against the surface provided by the axial undercut and thereby enables a force transmission between the two interfaces in the direction of the cup axis without an undesired linear movement occurring as a result between the two interfaces.In a further embodiment of the invention, it is provided that the suction cup has a first interface at a cup mouth, that the intermediate ring is accommodated between the suction cup and the carrier ring, and that the carrier ring is provided at an axial end region with a fourth interface which is designed for coupling with the first interface of the suction cup, wherein the first interface and the fourth interface are designed as a positive connection from the group: snap connection with a snap-in groove which runs around at least in regions and is recessed in the radial direction and with a snap-in projection which runs around at least in regions and projects in the radial direction, bayonet connection with an axial undercut and a support projection which is designed for axial support at the axial undercut. In this embodiment of the suction cup, the intermediate ring is accommodated between the suction cup and the carrier ring, the positive locking takes place between the suction cup and the carrier ring, so that the intermediate ring only has to be designed such that it can be connected at least largely sealingly to the suction cup and the carrier ring, without however being incorporated into the force flow between the suction cup and the carrier ring. The positive connection between the first interface on the suction cup and the fourth interface on the carrier ring can be configured either as a locking connection or as a bayonet connection in the same way as in the preceding embodiment.It is expedient if the intermediate ring bounds a perforated plate through which a multiplicity of bores pass, each of which has a cross-sectional area which is less than 5 percent of a cross-sectional area of an inner diameter of the intermediate ring. The perforated plate serves, in a similar manner to the vacuum channels arranged on the cup base, to enable the most homogeneous possible distribution of the negative pressure to the handling object. Furthermore, the perforated plate has the task of limiting a deformation of the handling object in order to avoid damage to the handling object. This applies in particular to the case where sensitive food or film bags are to be lifted and deposited with the suction cup.It is preferably provided that the axial end region of the carrier ring and the sealing ring form a latching connection with a latching groove which runs around at least in regions and is recessed in the radial direction and with a latching projection which runs around at least in regions and projects in the radial direction, or that the sealing ring is fixed firmly in a material-bonded manner to the axial end region of the carrier ring by an axially aligned end face. The fixing of the sealing ring to the carrier ring depends essentially on the material selection for the sealing ring. It is preferably provided that the sealing ring is made of a rubber-elastic material, in particular silicone or acrylonitrile butadiene rubber (NBR), or of a foam, in particular of a polyurethane or a chloroprene rubber, which is also sold under the name neoprene, or an ethylene propylene diene rubber (EPDM). A locking connection can be selected for a sealing ring made of silicone; a cohesive connection is preferable for a sealing ring made of NBR or of foam.It is advantageous if a circumferential sealing ring is arranged between a circumferential surface of the suction cup and an oppositely arranged circumferential surface of the intermediate ring, and / or if an O-ring is arranged between a circumferential surface of the intermediate ring and an oppositely arranged circumferential surface of the carrier ring. This measure increases the sealing effect between the suction cup and the intermediate ring or between the carrier ring and the intermediate ring, so that the requirements for dimensional accuracy of the circumferential surfaces can be reduced, since the O-ring ensures a certain tolerance compensation.Advantageous embodiments of the invention are shown in the drawing. The following shows: FIG. 1 shows a perspective illustration of a first embodiment of a suction cup, which comprises a suction cup, an intermediate ring, a carrier ring and a sealing ring, FIG. 2 shows a sectional front view of the suction cup according to FIG. 1, FIG. 3 is a sectional front view of the intermediate ring according to FIG. 1 , FIG. 4 is a sectional front view of the carrier ring according to FIG. 1 , FIG. 5 is a sectional front view of the sealing ring according to FIG. 1, FIG. 6 is an exploded, cross-sectional perspective view of the components of the suction cup of FIG. 1; and FIG. 7 is a sectional perspective exploded view of a second embodiment of a suction cup.A suction cup 1 shown in FIG. 1 is provided for use with a not-shown handling device, which can be, for example, a robot arm of an industrial robot or a multiaxial handling system constructed from linear axes. The suction cup serves for adhesion to a not-shown handling object, which, when the suction cup adheres, can be lifted at one location with the handling device and displaced to another location and deposited there. For this purpose, a vacuum is provided at a vacuum connection 14 of the suction cup 1, with which vacuum temporary suction of the suction cup 1 on a surface of a not-shown handling object can be brought about. In order to cancel the adhesion of the suction cup 1 to the handling object, provision can be made for a slight overpressure to be provided for a short time via the vacuum connection 14, with the result that the suction cup 1 can be released from the handling object.The suction cup 1 is modular in construction in order to enable adaptation to different use conditions, in particular different handling objects. The suction cup 1 comprises the components: suction cup 2, intermediate ring 3, carrier ring 4, sealing ring 5. Purely by way of example, it is provided that the components of the suction cup 1, apart from minor exceptions, are designed rotationally symmetrical to the cup axis 6. Furthermore, it is provided that the components of the suction cup 1, with the exception of the sealing ring 5, which can be produced in particular from a rubber-elastic material such as silicone or NBR, are produced from materials which, during intended use of the suction cup 1, experience no, or at least no appreciable elastic or plastic deformation and can therefore also be referred to as dimensionally stable. It is preferably provided that the suction cup 2, the intermediate ring 3 and the carrier ring 4 are each formed as plastic parts which are produced in a plastic injection molding process or in a generative production process, in particular laser sintering.As can be seen from the illustration in FIG. 1, a bayonet connection 51 is formed between the carrier ring 4 and the intermediate ring 3, so that the carrier ring 4 with the sealing ring 5 attached thereto can be removed from the intermediate ring 3 in a simple manner and preferably without tools by a user and can be replaced by another carrier ring 4 with sealing ring 5. The bayonet connection 51 is formed by a third interface 52, referred to as an axial undercut, on the intermediate ring 3 and a supporting projection, supported thereon and embodied purely by way of example in an L-shape as a fourth interface 53, on the carrier ring 4 and is described in more detail below.The intermediate ring 3 is positively secured to the suction cup 2 in the axial direction along the cup axis 6 by a latching connection 61 described in more detail below. The sealing ring 5 is positively secured to the carrier ring 4 in the axial direction along the cup axis 6 by a locking connection 81 described in more detail below.As can be seen from the sectional representations of FIGS. 2 and 3, the suction cup 2 has a cup base 11 which, purely by way of example, is designed in the shape of a cone segment and is provided in a central region with the vacuum connection 14 aligned coaxially with the cup axis 6. The vacuum connection 14 is formed, for example, as a tubular connection piece which delimits a connection bore, referred to as a fluid bore 17, which is provided with an internal thread 18. As a result, the vacuum connection 14 can be screwed to a connection piece, not shown, of a likewise not shown handling device, whereby both a mechanical fixing to the handling device and a vacuum provision from the handling device to the suction cup 1 are made possible.Adjacent to the cup base 11, a substantially circular cylindrical cup wall 12 extends along the cup axis 6, which defines a cup mouth 13 at an end region facing away from the cup base 11. Projections 20 which are aligned in the axial direction and are formed in the shape of a segment of a circular ring protrude from an axial end face 19 of the cup wall 12 which is formed in the shape of a circular ring and which are provided for a mechanical interaction with the intermediate ring 3 which will be described in more detail below. Furthermore, the cup wall 12 is provided on a purely exemplarily circular cylindrical, circumferential inner surface, which is also referred to as first interface 21, with a latching groove 22 extending outwards in the radial direction, which is also configured for a mechanical interaction with the intermediate ring 3 described in more detail below. A radial extension of the latching groove 22 is selected such that when the suction cup 2 is produced in a plastic injection molding process and the suction cup 2 is removed from the mold along the cup axis 6, no slide is required in the injection mold.Furthermore, a plurality of projections 15 extend from an inner surface 23 of the cup base 11 in the axial direction along the cup axis 6, which projections are spaced apart from one another in such a way that they delimit vacuum channels 16. These vacuum channels 16 are connected to the fluid bore 17 in a fluidically communicating manner, so that when a vacuum is provided to the fluid bore 17, a vacuum supply of all vacuum channels 16 is ensured. Purely by way of example, the projections 15 are designed as pins with a circular cross section and are each aligned parallel to the cup axis in order to promote production of the suction cup 2 in a plastic injection molding process.The intermediate ring 3 comprises a base body 31 which is of circular ring shape and from which, according to the representations of FIGS. 2 and 3, a coupling ring 32 extends upward in the axial direction and a second coupling ring 33 extends downward in the axial direction. The first coupling ring 32 has an outer circumferential surface which is of circular cylindrical configuration and is designated as a second interface 37 and from which a circumferential latching projection 34 extends outwards in the radial direction. The second interface 37 is adapted to the first interface 21 of the suction cup 2 in such a way that when the first coupling ring 32 is inserted into the cup mouth 13 of the suction cup 2, an at least substantially fluid-tight coupling is achieved between these two components. Furthermore, the latching groove 22 of the first interface 21 of the suction cup 2 and the latching protrusion 34 of the intermediate ring 3 are matched to one another in such a way that the latching protrusion 34 can be received in the latching groove 22 in a positive-locking manner and as a result an axially positive-locking between the suction cup 2 and the intermediate ring 3 is ensured.The intermediate ring 3 has an annular collar 35 which extends radially outwards from the outer circumferential surface, referred to as the second interface 37, of the first coupling ring 32. The annular collar 35 is provided locally with interruptions 39 which make it possible to mount the supporting projection arranged on the carrier ring 4 and designated as fourth interface 53. An upper side 38 of the annular collar 35 which is oriented in the axial direction and is designed in the form of a segment of a circular ring forms the axial undercut 52, against which the supporting projection of the carrier ring 4 which is designated as the fourth interface 53 comes to rest, as is shown in FIG. 1.Purely by way of example, the second coupling ring 33 of the intermediate ring 3 is provided at the end with a perforated plate 36, which extends virtually over the entire cross section of the intermediate ring 3 and which is provided with a multiplicity of bores 40. The perforated plate 36 serves for the most homogeneous possible distribution of the negative pressure that can be provided via the vacuum connection 14 and limits a deformation of the not-shown handling object.The carrier ring 4 likewise has a base body 41 which is of circular ring shape and from which, according to the representations of FIGS. 1 to 6, the fourth interfaces 53 which are designed as support projections and are arranged, for example, at a 90-degree pitch, project upwards in the axial direction. The carrier ring 4 can thereby be locked in a positive-locking manner by a linear approach movement to the intermediate ring 3 along the cup axis 6 and a subsequent rotational movement relative to the intermediate ring 3 about the cup axis 6.Furthermore, starting from the base body 41, a coupling ring 42 extends downward in the axial direction, which coupling ring has an outer circumferential surface 43, from which a latching projection 44 projects outward in the radial direction. The sealing ring 5 has a circumferential latching groove 72 on an inner surface 71 which is purely exemplarily circular-cylindrical and is provided for an engagement of the latching protrusion 44 of the carrier ring 4 in order to form a latching connection 81.The embodiment of the suction cup 101 according to FIG. 4 differs with regard to the configuration of the intermediate ring 103, the carrier ring 104 and the sealing ring 105, so that the following description is directed exclusively to these two components, while a description of the suction cup 2 formed identically to the first embodiment according to FIGS. 1 to 6 can be dispensed with.In contrast to the embodiment of the intermediate ring 3 according to FIGS. 1 to 6, the intermediate ring 103 does not have a perforated plate. The intermediate ring 103 can also be used instead of the intermediate ring 3 without other changes in the first embodiment according to FIGS. 1 to 6.In contrast to the configuration of the carrier ring 4 according to FIGS. 1 to 6, the carrier ring 104 has an underside 145 which is of circular ring shape and is provided for a cohesive fixing of the sealing ring 105 which is of circular ring shape purely by way of example. By way of example, it is provided that the sealing ring 105 is firmly bonded to the underside 145 of the carrier ring 104, in particular using a double-sided adhesive tape or a curable liquid adhesive.The combination of carrier ring 104 and sealing ring 105 can likewise be used directly with the components suction cup 2 and intermediate ring 3 according to FIGS. 1 to 6, without further modifications being required for this purpose.

Claims

Suction cup (1; 101) for a handling device, having a suction cup (2) which is provided with a vacuum connection (14) on a cup base (11) and which is connected to an intermediate ring (3; 103) at a cup mouth (13), wherein the intermediate ring (3; 103) is provided with a carrier ring (4; 104) at an axial end region which is remote from the suction cup (2), and wherein the carrier ring (4; 104) is provided with a sealing ring (5; at an axial end region which is remote from the intermediate ring (3; 103); 105), which is designed for sealing contact with a handling object, characterized in that a plurality of vacuum ducts (16) are formed on an inner surface (23) of the cup base (11) of the suction cup (2), which vacuum ducts are connected in a fluidically communicating manner to a connection bore (17) of the vacuum connection (14) and which are bounded by a plurality of projections (20) arranged at a distance from one another and protruding in the axial direction.Suction cup (1; 101) according to claim 1, characterised in that the suction cup (2) has a first interface (21) at a cup mouth (13) and that the intermediate ring (3; 103) is provided at mutually opposite axial end regions with a second interface (37) and with a third interface (52), wherein the second interface (37) is designed for coupling with the first interface (21) of the suction cup (2), and that the carrier ring (4; 104) is provided at an axial end region with a fourth interface (53), which is designed for coupling with the third interface (52) of the intermediate ring (3; 103).Suction cup (1; 101) according to claim 2, characterised in that the first interface (21) and the second interface (37) and / or that the third interface (52) and the fourth interface (53) are formed as a positive connection from the group: locking connection with a locking groove (22) running around at least in regions and recessed in the radial direction and with a locking projection (34) running around at least in regions and protruding in the radial direction, bayonet connection (51) with an axial undercut (52) and a support projection (53) formed for axial support on the axial undercut (52).Suction cup (1; 101) according to claim 1, characterised in that the suction cup (2) has a first interface (21) at a cup mouth (13), that the intermediate ring (3; 103) is accommodated between the suction cup (2) and the carrier ring (4; 104), and that the carrier ring (4; 4; 103); 104) is provided at an axial end region with a fourth interface (53), which is designed for coupling to the first interface (21) of the suction cup (2), wherein the first interface (21) and the fourth interface (53) are designed as a form-fit connection from the group: latching connection with an at least partially encircling latching groove (22) recessed in the radial direction and with an at least partially encircling latching protrusion (34) protruding in the radial direction, bayonet connection (51) with an axial undercut (52) and a supporting protrusion (53) designed for axial support on the axial undercut (52).Suction cup (1; 101) according to one of the preceding claims, characterized in that the intermediate ring (3; 103) borders (36) a perforated plate (36), through which a plurality of bores (40) pass, each of which has a cross-sectional area which is less than 5 percent of a cross-sectional area of an inner diameter of the intermediate ring (3; 103).Suction cup (1; 101) according to one of the preceding claims, characterized in that the axial end region of the carrier ring (4; 104) and the sealing ring (5; 105) form a latching connection (81) with a latching groove (72) which runs circumferentially at least in regions and is recessed in the radial direction and with a latching projection (44; 144) which runs circumferentially at least in regions and projects in the radial direction, or in that the sealing ring (5; 105) is fixed firmly to the axial end region of the carrier ring (4; 104) by means of an axially aligned end face (145).Suction cup (1; 101) according to one of the preceding claims, characterized in that the sealing ring (5; 105) is produced from a rubber-elastic material, in particular silicone or acrylonitrile butadiene rubber, or from a foam, in particular from a polyurethane or a chloroprene rubber or an ethylene propylene diene rubber.Suction cup (1; 101) according to one of the preceding claims, characterized in that a circumferential sealing ring is arranged between a circumferential surface (21) of the suction cup (2) and an oppositely arranged circumferential surface (37) of the intermediate ring (3; 103), and / or in that a circumferential sealing ring (105) is arranged between a circumferential surface of the intermediate ring (3; 103) and an oppositely arranged circumferential surface of the carrier ring (4; 104).

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