Driving a gripper using a suction cup

Abstract

Gripper (2) for gripping an object (6), with a base body (10) for fastening the gripper (2) to a guide part (4), with at least one gripping element (14) movable by a gripping movement (18) relative to the base body (10) along a gripping path (16), with at least one actuator (20) for generating the gripping movement (18) of at least one of the gripping elements (14), wherein the actuator (20) contains: - a suction surface (24) movable relative to the base body (10) along a suction path (26) by a suction movement (28), - wherein the suction surface (24) is motion-coupled to at least one of the gripping elements (14) such that the suction movement (28) of the suction surface (24) along the suction path (26) leads to the gripping movement (18) of the gripping element (14), - and a pneumatically actuated suction cup (22), wherein the suction cup (22) has a fixing end (30) attached to the base body (10) and an open suction end (32) pneumatically tightly abutting the suction surface (24), wherein the suction end (32) and the fixing end (30) are connected to one another via a flexible cup section (34), - wherein the suction end (32) is attached to the suction surface (24) in that it is sucked onto the suction surface (32) as soon as the suction cup (22) is subjected to negative pressure, - wherein the suction end (32) always lies tightly against the suction surface (24), even when the suction cup (22) is not subjected to negative pressure, in that the suction cup (22) is already slightly compressed in this case by the mechanical conditions in the gripper (2), - wherein the suction cup (22) is designed such that, upon pneumatic actuation thereof at its pneumatic connection (36), the suction end (32) moves along the suction path (26) with deformation of the cup section (34) and with suction-like entrainment of the suction surface (24).

Description

[0001] The invention relates to grippers, such as those used in manufacturing / automation technology. Such a gripper is, for example, attached to the free end of a robot arm or another generally movable part of a production system. Such grippers are then used in the manufacturing process to grip / release objects in order to handle them, for example, to relocate them, hold them for processing, assemble them with other components, etc. The grippers in question are also referred to as gripper arrangements, robot grippers, or gripping systems.

[0002] For example, DE 10 2007 056 577 A1 discloses a gripper assembly for a robot for gripping a cylindrical and / or annular workpiece. It comprises at least one pair of gripper fingers that grip the workpiece from the outside or, in the case of an annular workpiece, from the inside. It also comprises a housing for holding the individual components of the gripper assembly, which can be connected to the free end of an arm of the robot. An electric motor, which can be controlled by a programmable logic controller (PLC), is provided to drive the respective finger of at least one gripper pair.

[0003] From DE 696 01 022 T2 a gripping pliers is known, with a vacuum actuating element between gripping elements in order to act on the gripping elements to close the pliers.

[0004] From JP 2019-034399 A a gripping device is known which drives holding means with the aid of expansion means made of flexible material which expand or contract due to pressure changes.

[0005] The invention is based on the object of proposing improvements with regard to a gripper.

[0006] This object is achieved by a gripper according to claim 1. Preferred or advantageous embodiments of the invention, as well as other categories of the invention, emerge from the further claims, the following description, and the accompanying figures. The gripper serves to grip or release an object as needed.

[0007] The gripper contains a base body, which can be designed, for example, as the gripper housing or another structural component. This serves directly or indirectly to attach the gripper to a guide component. The guide component is a device that supports, holds, or guides the gripper, for example, the free end of a robot arm, a—usually movable—structural component of a production system, etc.

[0008] The gripper also contains at least one gripping element, also called a gripper finger, that is movable relative to the base body. The movement performed by the gripping element, or a fixed point of the gripping element engaging the object, relative to the base body is referred to here as the gripping movement. The gripping movement follows or runs along a gripping path. It begins, in particular, in a resting or starting position with the object not yet grasped and ends in a gripping position in which the object is then grasped.

[0009] The gripper also contains an actuator. This serves to generate the gripping movement of the gripping element, i.e., the necessary movement stroke and gripping force. The actuator thus mechanically drives the gripping element so that it can perform its gripping movement. The actuator contains a suction surface. This is movable relative to the base body. The suction surface is, in particular, the surface of a component of the gripper and therefore not necessarily a separate volume component.

[0010] The mobility or movement of the suction surface or of a fixed point thereof runs along a suction path. The suction path can be a straight line or a curve, in particular a section of a circular path. The movement of the suction surface is referred to here as the suction movement. The suction surface is motion-coupled to the gripping element. This motion coupling is designed in such a way that the suction movement of the suction surface along the suction path leads to or causes the gripping movement of the gripping element; in particular, the gripping movement of the gripping element also leads to a suction movement of the suction surface along the suction path (especially when the object is released, i.e. in the opposite direction of the gripping / suction movement). The motion coupling therefore transfers the suction movement of the suction surface along the suction path into a gripping movement of the gripping element relative to the base body.

[0011] The actuator contains a suction cup. Such a suction cup is also referred to as a suction cup, vacuum suction cup, bellows, etc. The suction cup is pneumatically actuated. This actuation is, in particular, an evacuation of the suction cup or its interior, i.e., its application of a negative pressure / "vacuum" relative to the environment. The interior is created, formed, or sealed by the object to be sucked, in this case the suction surface, closing the suction cup at its open suction end - which is open for contact with an object to be sucked in. The suction cup has a fixing end attached to the base body and a suction end that fits pneumatically tightly against the suction surface. The suction end and the fixing end are connected to each other via a flexible cup section. The suction cup is pneumatically actuated at its pneumatic connection. As soon as the suction cup is subjected to negative pressure there, it attaches itself to a counter surface, in this case the suction surface.Pneumatic actuation is therefore an evacuation of the interior of the suction cup or the creation of a negative pressure inside the suction cup.

[0012] The suction cup is designed so that when pneumatically actuated (“active state”, applying negative pressure to the suction cup), the suction end moves along the suction path, deforming the cup section and drawing the suction surface along with it. This movement occurs particularly towards the fixing element. In other words, when pneumatically actuated, the suction cup draws its suction end towards the fixing element, drawing the suction surface along with it. The suction movement therefore corresponds to the contraction movement of the suction cup when pneumatically actuated. The suction end therefore moves relative to the fixing element because the cup section between the suction end and the fixing element contracts, while the fixing element is fixed to the base body. The cup section deforms / moves; here various movement components (contraction, invagination, contraction of a bellows, etc.) can interact; in any case, a contraction of the entire suction cup occurs.This contraction movement creates the actual drive / stroke / force of the gripping element.

[0013] The suction cup thus forms the actual drive element in the gripper, or rather the drive or motor, which generates the force and stroke for the gripping movement. The deformation of the cup section, which otherwise occurs rather "parasitically" in such a suction cup, is deliberately exploited to generate the stroke or force path in the gripper, which ultimately generates the movement of the gripping element. Such a stroke is generated in gripper arms known from practice, for example, by an electric motor / electric linear drive, hydraulic or pneumatic cylinder, etc.

[0014] In the gripper, the suction end always lies close to the suction surface, even when the suction cup is not subjected to negative pressure (“passive state”). This is achieved because the suction cup is already slightly compressed in the passive state due to the mechanical conditions in the gripper - for example the distance between the suction surface and the fixing end. The suction cup, as an elastic, particularly springy, component (e.g. silicone / rubber material), is therefore permanently slightly compressed against its own internal stress. This ensures that a tight volume exists inside the suction cup when negative pressure is applied because the suction surface always seals the suction end (even in the passive state). In this way, the application of negative pressure can also lead to an immediate and reliable suction movement and thus a gripping movement.

[0015] The actual gripping of the gripper is achieved by applying a gripping area / gripping end of the gripping element to the object through the gripping movement, thereby gripping it, for example, frictionally, force-fitting, positively, etc. For this purpose, the gripping element can interact with a contact surface, e.g., a section of the base body, as a counterpart. Alternatively or additionally, several gripping elements can interact in the manner of gripping pliers. The actual gripping can therefore, in particular, involve bringing together or spreading apart gripping ends / gripping sections, etc.

[0016] The suction cup drives the gripper or its gripping elements / arms in a specific direction of movement, in particular the direction required to grip the object. The object is then released by the gripper arms returning. This returning is not carried out by an “active”, i.e. pneumatic or motor drive in the opposite direction, but rather, for example, by spring force, gravity, etc. In particular, a spring force is generated by the springback of the suction cup or a spring-loaded cup section deformed during gripping. However, external return / spring elements of any type can also be provided, which are arranged, for example, on the gripping element, the suction surface or a system part / gearbox (see below). The gripping elements are therefore driven by the actuators in particular by actively applying a drive force by means of negative pressure in only one direction of movement of the gripping movement.

[0017] The proposed gripper offers the advantage of being particularly simple and cost-effective in terms of its drive and force generation. In particular, no electric or electric motor drive is required. A pneumatic or vacuum source, etc., is usually available anyway, especially in a production facility where the gripper is to be used.

[0018] In particular, the gripper can also be provided with several gripping elements and / or several actuators that are interconnected in any desired manner, ie one or more actuators can each drive one or more of the gripping elements.

[0019] In a preferred embodiment, the actuator contains a contact part for the suction cup. The contact part has the suction surface. Therefore, the contact part and, together with it, the suction surface, are movable relative to the base body along the suction path due to the suction movement. The contact part, like the suction surface, is motion-coupled to the gripping element in such a way that the suction movement of the contact part along the suction path leads to the gripping movement of the gripping element, and in particular vice versa. The contact part thus represents a type of suction piece / plate that acts as a counterpart for the suction cup, against which the latter rests or is sucked. The motion coupling is therefore analogous to that described above, only for the entire contact part and not just for the suction surface. The contact part can have any shape. The only decisive factor is that it offers the possibility of tightly contacting the suction end with the suction surface.This embodiment offers the possibility of providing intermediate elements, such as a deflection, a gear, etc., between the linkage element and the gripping element in order to be able to realize any complex gripping elements or grippers or corresponding gripping movements.

[0020] In a preferred embodiment, at least one, and in particular all, of the suction surfaces are part of the surface of the gripping element(s). The suction cup then generates the gripping movement directly on the gripping element. In this case, the gripping element thus comprises a "part" of the actuator, namely its suction surface. This allows a gripper to be realized with a particularly small number of individual parts.

[0021] In a preferred embodiment, the gripper contains at least one articulation element that is mechanically or motion-coupled between the system part and the gripping element. This articulation element is designed to convert the suction movement of the system part along the suction path into the gripping movement of the gripping element along the gripping path relative to the base body. The articulation element thus effects a movement coupling of the actuator or its suction surface and the gripping element via the system part. The articulation element can be rigid and / or rigidly connected to the system part and / or the gripping element. In particular, a one-piece design of the gripping element and / or articulation element and / or system part is thus possible. However, the articulation element can also be designed with any desired complexity, for example as a cable pull or lever arrangement, etc. In particular, an articulation element can be provided to transmit the movement of a single actuator to multiple gripping elements or vice versa.

[0022] In the above-mentioned case where the gripping element directly has the suction surface, one could also say that the linkage element and the system part degenerate into a zero element, since their interposition between the gripping element and the suction surface is omitted or they are designed in one piece with the gripping element.

[0023] In a preferred embodiment, at least one, and in particular all, of the linkage elements is a gear mechanism. "Gear mechanism" is to be understood here in the broad sense and includes—individually or in combination—lever, joint, gear, rack, cable, and other transmission means.

[0024] In a preferred embodiment, at least one, and in particular all of the suction cups are commercially available standard components. “Standard component” is to be understood as meaning that it is available in many variants and / or from a variety of suppliers. In particular, it is a COTS (components / commercial off the shelf) component. Such suction cups are also referred to as “vacuum actuators” and are used in particular for sucking on and releasing components in a production plant. In this case, the standard component is being used for a purpose other than that for which it was intended: the suction end is always close to the suction surface. This suction surface is never “released”. In the usual use of such a suction cup, it is used to “grip” an object by directly sucking it onto it. In this case, the gripping is carried out by the gripping element. The suction cup merely serves as a “motor” or “drive” for the gripping element.The object of the suction action of the suction cup is therefore not the object to be gripped itself, but the suction surface in the gripper as a force transmission element.

[0025] In a preferred embodiment, at least one, and in particular all, of the suction cups in the gripper are replaceable. Thus, a suction cup that shows material fatigue after a certain number of uses, e.g., wear of the cup section, can be replaced with another of the same design or an alternative suction cup. This essentially corresponds to replacing the "motor" in the gripper. The replacement can thus be carried out particularly easily and cost-effectively – especially in contrast to replacing an electric motor / hydraulic cylinder / pneumatic cylinder.

[0026] In a preferred embodiment, at least one, and in particular all, of the gripping elements is a linear slide guided on the base body. The gripping movement for gripping the object is thus also a linear movement along a straight line as the gripping path with respect to the base body, which is made possible by this embodiment.

[0027] In a preferred embodiment, at least one of the gripping elements is a pivot arm mounted on the base body so as to be pivotable about a pivot axis. The gripping movement for gripping the object is thus a pivoting or circular movement with respect to the base body around the pivot axis along a circular gripping path, which is made possible by this embodiment. Here, in particular, the combination with the above-mentioned embodiment provides that the pivotable pivot arm(s) (in particular gripping tongs, see below) directly have the suction surfaces. A pivoting movement of the suction surface relative to the fixing end of the suction cup fixed to the base body is then compensated for by a deformation of the flexible cup section.

[0028] In a preferred embodiment, the gripper comprises at least two gripping elements movably mounted on the base body, which cooperate to form at least one gripping tong. The interacting gripping elements can be driven by a common or individual actuator and / or linkage element. One, several, or all of the gripping elements of the gripping tong can, in particular, be the aforementioned linear slides or pivot arms. This enables the gripper to perform tong-like / clamp-like gripping movements.

[0029] In a preferred embodiment, the gripper contains at least one pneumatic line leading from the pneumatic connection of the suction cup to a connection end. The pneumatic line is, in particular, integrally formed in the base body. This is achieved in particular by producing the base body using an additive manufacturing process, in particular 3D printing. Thus, a pneumatic supply or a connection end of the supply for the suction cup can be routed to any location on the gripper, in particular on the base body, and does not have to be located directly on the suction cup.

[0030] In particular, gripping elements manufactured using 3D printing allow for a free design and particularly free adaptability of the gripping element or gripper to the objects / products to be gripped. This also makes it particularly easy to scale the gripping element / gripper (changing the size without altering the basic structure). In other words, the gripper can be adapted to an intended object, for example, to optimize the gripping process. This can be achieved, in particular, by exchanging one gripping element for another on the same base body.

[0031] For the gripping elements, stop elements can be provided on the base body or through additional elements that can be attached to the base body. These then limit, for example, the opening and / or closing stroke of a gripping element.

[0032] The gripper can be designed either in such a way that an object is gripped or released by the gripping element(s) when negative pressure is applied to the suction cup.

[0033] In a preferred embodiment, the gripper has at least one channel and / or at least one sensor receptacle and / or at least one connection and / or at least one interface. These are in particular air or pneumatic channels as channels, in particular for supplying the suction cups / suction elements, receiving spaces / interfaces / bores etc. or other - in particular mechanical - receptacles, interfaces etc. for sensors, additional components etc. with which the gripper, in particular on the base body, is to be equipped. Such an interface can also be one to the guide part, for example a form-fitting element, a thread, a bore, an undercut or the like. The corresponding channels / receptacles / connections / interfaces are then all in particular integral components of the gripper, in particular of the base body. In particular if the gripper orat least parts of which are manufactured using an additive manufacturing process, the integration of the relevant holders, interfaces, etc. is particularly simple or these are manufactured using the additive manufacturing process together with the gripper or its components (base body, gripping element, system part, articulation element, ...) - in particular in one piece.

[0034] In a preferred embodiment, the gripper contains at least one additional pneumatically (in particular by negative pressure) actuated suction element for sucking up an object. The suction element can be another suction cup or another pneumatically, in particular by negative pressure, operated suction element, for example a suction plate or similar. The "object" referred to here can be understood to be the same object that is to be gripped by the gripping element. The additional suction element then serves, for example, to support the gripping. Alternatively or additionally, the "object" can also be another object that is different from the object mentioned above, i.e., deviates from it. The gripper is then equipped to pick up, transport, hold, etc., multiple objects. The additional suction element can be attached in particular to the base body, but also to the gripper arm or another structural part of the gripper.The pneumatic connections of the suction cup(s) and the additional suction element(s) can be combined or designed separately for the respective suction element to be supplied.

[0035] In a preferred embodiment, at least part of the gripper - e.g. all components with the exception of the suction cup - is manufactured using an additive manufacturing process. The suction cup may be excluded because it is usually made of a flexible material such as rubber or silicone and therefore cannot be manufactured using a manufacturing process that is suitable for manufacturing the rest of the gripper. Should this nevertheless be possible, the suction cup can also be manufactured using the additive manufacturing process or an additive manufacturing process. The manufacturing process is in particular 3D printing. In particular, the entire gripper, with the exception of the parts that cannot be manufactured using the selected manufacturing process, such as the suction cup / suction element / screws / pins / seals, etc., is manufactured using the same or different additive manufacturing processes.Thus, the known advantages of such additive manufacturing processes, particularly with regard to the feasibility of complex shapes, also apply to the gripper in question.

[0036] The object of the invention is also achieved by a method according to patent claim 14. This serves to drive the gripping element of the gripper according to the invention, as explained above. In the method, the suction cup is pneumatically actuated, in particular evacuated, at its pneumatic connection. As a result, the suction end of the suction cup is moved along the suction path, deforming the cup section. In particular, the suction end is moved towards the fixing end. Since the suction end is firmly suctioned to the suction surface, the movement of the suction end causes the suction surface to be carried along the suction path. As a result, the suction surface is also moved - in particular towards the fixing end - or this corresponding movement is driven by the contracting suction cup. The movement or drive of the suction surface represents a drive stroke in the gripper and generates a driving force therein.Via the movement coupling of the suction surface with the gripping element, the suction movement of the suction surface, i.e. the drive stroke, leads to the gripping movement of the gripping element, so that ultimately the gripping element is driven by the working stroke generated by the actuator or the contracting suction cup.

[0037] The method and at least some of its possible embodiments as well as the respective advantages have already been explained in connection with the gripper according to the invention.

[0038] The object of the invention is also achieved by the use of a suction cup according to claim 14 in the method explained above. Thus, a suction cup intended for the direct gripping of an object is misused as explained above. It is used as a drive element or lifting or force-generating element in a gripper or its actuator and thus not for the direct gripping of the object. Direct gripping would occur by placing the suction cup against a corresponding counter surface of the object and therefore not, as in the present case, against a suction surface specifically provided for this purpose in the actuator.

[0039] The use and at least some of its possible embodiments as well as the respective advantages have already been explained in connection with the gripper according to the invention and the method according to the invention.

[0040] Further features, effects, and advantages of the invention will become apparent from the following description of preferred embodiments of the invention and the accompanying figures. Each of these figures shows a schematic diagram: Fig. 1 a gripper a) before and b) after driving its gripping element as a linear slide, Fig. 2 an alternative gripper with contact part and linkage element a) before and b) after driving its gripping element, Fig. 3 an alternative gripper with gear a) before and b) after driving its gripping elements as gripping tongs made of swivel arms, Fig. 4 an alternative gripper without a system part a) before and b) after driving its gripping elements as a gripper made of swivel arms.

[0041] Fig. Figure 1 shows a gripper 2, in this case a robot gripper. This is attached to a guide part 4, in this case the free end of a robot arm (not shown in detail). The robot arm moves the entire gripper 2 in a production facility (not shown in detail) to grip or lift an object 6, in this case a component to be processed in the production facility, from a base 8 and later set it down again. Fig. 1a) shows a situation before the gripper 2 picks up the object 6. The object is still resting on the base 8. Fig. 1b), on the other hand, shows a situation after the gripper 2 has gripped and held the object 6 and lifted it from the base 8.

[0042] The gripper 2 has a base body 10, which in turn contains a mechanical interface 12 to the guide part 4. The interface 12 is a specially shaped flange, indicated only symbolically here, tailored to the guide part 4, which is held in a corresponding fastening means on the guide part 4, so that the entire gripper 2 is held on the guide part 4.

[0043] The gripper 2 further comprises a gripping element 14, which is mounted movably along a gripping path 16 relative to the base body 10. Due to its movement along the gripping path 16, the gripping element 14 performs a Fig. 1 performs a gripping movement 18 indicated by an arrow. The gripping path 16 is a straight line here, and the gripping movement 18 is therefore a linear movement. The gripping element 14 is therefore a linear slide 58 guided in the base body 10.

[0044] The gripper 2 further contains an actuator 20. This serves to cause the gripping movement 18 or the necessary drive for the gripping element 14. The actuator 20 contains a suction cup 22 and a suction surface 24. The suction surface 24 is movable relative to the base body 10 along a suction path 26. During the corresponding movement, the suction surface 24 performs a suction movement 28, again indicated here by an arrow, along a suction path 26. The suction path 26 is also a straight line here.

[0045] The suction surface 24 is motion-coupled to the gripping element 14, in this case in that the suction surface 24 is a portion of the surface of the gripping element 14. Due to the motion coupling, the suction movement 28 of the suction surface 24 leads to the gripping movement 18 of the gripping element 14, which is identical in direction and amplitude to the suction movement 28. In this case, the suction path 26 is therefore predetermined or achieved by the guidance of the gripping element 14 on the base body 10.

[0046] The actuator 20 also includes the suction cup 22, which is pneumatically actuated. The suction cup 22 has a fixing end 30 and a suction end 32. The suction end 32 and the fixing end 30 are connected to each other by or via a flexible cup section 34. The suction end 32 lies pneumatically tightly against the suction surface 24. In other words, the suction surface 24 seals an interior space 38 of the suction cup 22 in a pneumatically sealed manner.

[0047] The suction cup 22 also has a pneumatic connection 36. In the example, this is located at the fixing end 30. The pneumatic actuation of the suction cup 22 occurs by applying a negative pressure to the pneumatic connection 36. This leads to a negative pressure or evacuation of the interior 38. The cup section 34 deforms to reduce the volume of the interior 38. As a result, the suction end 32 moves toward the fixing end 30. Due to the suction on the suction surface 24, the suction surface 24 is entrained or driven during this movement. Via the movement coupling with the suction surface 24, the gripping element 14 is also entrained or driven and performs the gripping movement 18.

[0048] Fig. Figure 2b shows, among other things, the deformed cup section 34 due to the reduced interior space 38 due to pneumatic negative pressure. The pneumatic actuation or evacuation of the actuator 20 is carried out by supplying a negative pressure to the pneumatic connection 36 via a negative pressure or pneumatic line 42 (not explained in detail).

[0049] The object 6 is gripped by the gripper 2 by being pressed against a contact surface 40 of the base body 10 via the gripping movement 18. Gripping is thus effected by frictional engagement, with a gripping area 43, here the angled end of the gripping element 14 in the form of a gripping arm, resting on the object 6.

[0050] Fig. 2 shows an alternative gripper 2. Accordingly Fig. 1 are in the Fig. 2a) and Fig. 2b) again shows the states before and after grasping and picking up the object 6. In contrast to Fig. 1, the gripping element 14 does not have the suction surface 24. Instead, the actuator contains a contact part 44 that has the suction surface 24. The suction cup 22 thus rests with its suction end 32 on the contact part 44 or its suction surface 24 in a pneumatically sealed manner. The contact part 44 is movably mounted or guided relative to the base body 10, so that it can execute the suction movement 28 along the suction path 26.

[0051] In order to achieve the above-mentioned movement coupling of the suction surface 24 with the gripping element 14, the contact part 44 is movement-coupled to the gripping element 14 in such a way that the suction movement 28 of the contact part 44 along the suction path 26 causes the gripping movement 18 of the gripping element 14 along the gripping path 16.

[0052] In order to realize this movement coupling, the gripper 2 contains a linkage element 46. In the embodiment according to Fig. 2, this is a rigid connecting element between gripping element 14 and contact part 44, which is firmly and rigidly attached to both elements. The entire structure comprising gripping element 14, articulation element 46, and contact part 44 is therefore a rigid arrangement. Due to the rigid connection, the suction movement 28 corresponds here again to the gripping movement 18. Gripping path 16 and suction path 26 are again straight lines. The direction and amplitude are identical. The guidance of the contact part 44, and thus of the suction surface 24, relative to the base body 10 is achieved by the latter being rigidly and firmly attached to the gripping element 14 by means of the articulation element 46, and the gripping element 14, in turn, being mounted on the base body 10 for linear displacement in a manner not shown.

[0053] In the Fig. 1 and Fig. 2, the gripping elements 14 are linear slides 58 guided on the base body.

[0054] In Fig. 2, the gripper 2 contains, in addition to the suction cup 22, which serves to drive the gripper 2 or the gripping element 14, an additional suction element 48, here also a suction cup. The suction element 48 is attached to the base body 10 by its fixing end 30. In this case, the suction element 48 serves to assist in gripping the object 6, in that the object 6 is sucked in by the additional suction element 48 and held on the base body 10, so that the holding is supported by the gripping element 14. The suction element 48 is supplied with negative pressure via a pneumatic line 42 in order to exert its suction effect. The pneumatic line 42 is integrated into the base body 10. The integration is achieved in such a way that the entire gripper 2, with the exception of the suction cup 22 and the suction element 48, is manufactured using an additive manufacturing process, in this case 3D printing.The pneumatic line 42 is manufactured integrally as a recess in the solid material, i.e., not subsequently inserted into the base body 10. The pneumatic line 42 leads from the suction element 48 or its pneumatic connection 36 to a connection end 54. There, the suction element 48 is supplied with negative pressure as needed.

[0055] Fig. 3 shows a further alternative embodiment of a gripper 2. This has two gripping elements 14 instead of just one, which here are not designed as linear slides, but as pivot arms 52 pivotally mounted on the base body 10. The pivoting movement takes place about a respective pivot axis 50. The gripping path 16 of the respective gripping element 14 is therefore a circular path around the pivot axis 50. The gripping movement 18 is also a circular segment movement along the gripping path 16. The cooperating gripping elements 14 form a gripping tong 64, here a spreading tong, for holding an object 6 by spreading and releasing the object by contracting.

[0056] Gripping movement 18 and suction movement 28 are in Fig. 3 are shown enlarged for the sake of clarity, but are carried out as before on the gripping track 16 or suction track 26.

[0057] As in the embodiment according to Fig. 2, a linkage element 46 is provided between a contact part 44 and the gripping elements 14 to effect the movement coupling between the suction surface 24 on the contact part 44 and the gripping elements 14. The contact part 44 itself is guided linearly on the base body 10 in a manner not shown, so that it can follow the linear suction movement 28.

[0058] The linkage element 46 is a gear 56, which is designed as a cable-driven gear. The linear movement of the suction surface 24 along the suction path 26 in a straight line, i.e., the linear suction movement 28, is converted via the gear 56 into the two gripping movements 18 of the pivot arms 14.

[0059] In this embodiment, the suction cup 22 or its pneumatic connection 36 is also supplied with negative pressure via a pneumatic line 42. This pneumatic line 42 is also Fig. 2 is realized within the base body 10 as a channel 60, in which the base body 10 is manufactured using the additive manufacturing process. Here, the interface 12 is also manufactured using the additive manufacturing process during the production of the base body 10, here as a special form-fitting element for connecting to the guide part 4 (not shown here).

[0060] Furthermore, a sensor receptacle 62, i.e., a mechanical mounting interface for a sensor 66, is manufactured in the base body 10 using the additive manufacturing process. The sensor 66 serves, in a manner not explained in detail, to detect the presence of an object 6, which is to be gripped by the gripper 2.

[0061] In all grippers 2 shown, the suction cups 22 are replaceable as wear parts. The suction cups 22 are purchased COTS standard components, which are actually intended by the respective manufacturer for the direct suction of objects 6, but are used here for a different purpose as a drive for the gripping elements 14.

[0062] The suction movement 28 thus represents a drive stroke 68 in the sensor 2, which is transmitted to the gripping element(s) 14 by the aforementioned movement couplings.

[0063] Fig. 4 shows another alternative gripper 2, in which - as in Fig. 3 - a gripper 64 is formed from two gripping elements 14 as pivot arms 52, which are also pivotally mounted about the pivot axes 50 on the base body 10. In contrast to the above, however, the gripping elements 14 here directly have the suction surfaces 24. The uneven contraction of the suction cups 22 or the cup sections 34 (application of negative pressure, Fig. 2a to Fig. 2b) compensates for the pivoting movement of the suction surfaces 24 about the pivot axes 50 in relation to the fixing ends 30 on the base body 10.

[0064] The suction of the suction cups 22 causes a release of the object 6, so that it can be moved according to Fig. 2b can be placed on the base 8.

[0065] Both suction cups 22 are connected here to the connection end 54 by a common channel 60 or suction line 42. When there is negative pressure at the connection end 54, both suction cups 22 and gripping elements 14 are actuated equally.

[0066] A stop element 70 is attached to the base body 10 as a separate component. In the gripping position of the object 6 according to Fig. 4a, the gripping elements 14 rest against this stop element 70, meaning this limits their movement path. Therefore, the object 6 is held only positively via the gripping lugs 72 of the gripping elements 14, but not force-fittingly. This allows the object 6 to be handled particularly gently.

[0067] In a dashed optional embodiment, additional spring elements 74, here coil springs, are provided, which are supported by exerting a compressive force between the base body 10 and gripping elements 14. These promote the return movement of the gripping element 14 from the position Fig. 4b after Fig. 4a, ie when removing the negative pressure in the suction cups 22, i.e. when gripping an object 6. The spring elements 74 also support or cause, if necessary completely, the reshaping of the cup sections 34 during the transition to the non-compressed state, i.e. from Fig. 4b to Fig. 4a. List of reference symbols 2 grippers 4 Guide part 6 Object 8 Base 10 basic bodies 12 Interface (to the guide part) 14 Gripping element 16 gripping track 18 Gripping movement 20 Actuator 22 suction cup 24 suction surface 26 suction track 28 Suction movement 30 fixators 32 sucking 34 Bowl section 36 Pneumatic connection 38 Interior 40 contact surface 42 Pneumatic line 43 Gripping area 44 Plant section 46 Linkage element 48 additional suction element 50 swivel axis 52 swivel arm 54 Connection end 56 gearboxes 58 linear slides 60 channels 62 Sensor recording 64 gripper 66 Sensor 68 drive stroke 70 stop element 72 Greifnase 74 spring element

Claims

[1] Gripper (2) for gripping an object (6), with a base body (10) for fastening the gripper (2) to a guide part (4), with at least one gripping element (14) movable by a gripping movement (18) relative to the base body (10) along a gripping path (16), with at least one actuator (20) for generating the gripping movement (18) of at least one of the gripping elements (14), wherein the actuator (20) contains: - a suction surface (24) movable relative to the base body (10) along a suction path (26) by a suction movement (28), - wherein the suction surface (24) is motion-coupled to at least one of the gripping elements (14) such that the suction movement (28) of the suction surface (24) along the suction path (26) leads to the gripping movement (18) of the gripping element (14), - and a pneumatically actuated suction cup (22), wherein the suction cup (22) has a fixing end (30) attached to the base body (10) and an open suction end (32) pneumatically tightly abutting the suction surface (24), wherein the suction end (32) and the fixing end (30) are connected to one another via a flexible cup section (34), - wherein the suction end (32) is attached to the suction surface (24) in that it is sucked onto the suction surface (32) as soon as the suction cup (22) is subjected to negative pressure, - wherein the suction end (32) always lies tightly against the suction surface (24), even when the suction cup (22) is not subjected to negative pressure, in that the suction cup (22) is already slightly compressed in this case by the mechanical conditions in the gripper (2), - wherein the suction cup (22) is designed such that, upon pneumatic actuation thereof at its pneumatic connection (36), the suction end (32) moves along the suction path (26) with deformation of the cup section (34) and with suction-like entrainment of the suction surface (24). [2] Gripper (2) according to claim 1, characterized by that the suction surface (24) is part of the surface of the gripping element (14). [3] Gripper (2) according to one of the preceding claims, characterized by in that the actuator (20) contains a contact part (44) which has the suction surface (24) and which is movable relative to the base body (10) along the suction path (26) by the suction movement (28), wherein the contact part (44) is movement-coupled to the gripping element (14) in such a way that the suction movement (28) of the contact part (44) along the suction path (26) leads to the gripping movement (18) of the gripping element (14). [4] Gripper (2) according to claim 3, characterized bythat the gripper (2) contains an articulation element (46) connected between the system part (44) and the gripping element (14), which is designed to convert the movement of the system part (44) along the suction path (26) into the gripping movement (18) of the gripping element (14) along the gripping path (16). [5] Gripper (2) according to claim 4, characterized by that the articulation element (46) is a gear (56). [6] Gripper (2) according to one of the preceding claims, characterized by that the suction cup (22) is a commercially available standard component. [7] Gripper (2) according to one of the preceding claims, characterized by that the suction cup (22) in the gripper (2) is replaceable. [8] Gripper (2) according to one of the preceding claims, characterized bythat at least one of the gripping elements (14) is a linear slide (58) guided on the base body (10) and / or at least one of the gripping elements (14) is a pivoting arm (52) pivotably mounted on the base body (10). [9] Gripper (2) according to one of the preceding claims, characterized by that the gripper (2) contains at least two gripping elements (14) which are movably mounted on the base body (10) and which cooperate to form gripping tongs (64). [10] Gripper (2) according to one of the preceding claims, characterized by that the gripper (2) contains a pneumatic line (42) leading from the pneumatic connection (36) of the suction cup (22) to a connection end (54). [11] Gripper (2) according to one of the preceding claims, characterized by that the gripper (2) has at least one channel (60) and / or at least one sensor receptacle (62) and / or at least one interface (12). [12] Gripper (2) according to one of the preceding claims, characterized by that the gripper (2) contains an additional suction element (48) for sucking the or another object (6). [13] Gripper (2) according to one of the preceding claims, characterized by that at least part of the gripper (2) is manufactured by an additive manufacturing process. [14] Method for driving the gripping element (14) of a gripper (2) according to one of the preceding claims, in which the suction cup (22) is pneumatically actuated at its pneumatic connection (36) so that the suction end (32) is moved along the suction path (26) with deformation of the cup section (34) and with suction-like entrainment of the suction surface (24), wherein, via the movement coupling of the suction surface (24) with the gripping element (14), the suction movement (28) of the suction surface (24) represents a drive stroke (68) in the gripper (2) which leads to the gripping movement (18) of the gripping element (14). [15] Use of a suction cup (22) in a method according to claim 14.

Images