Sauggreifer

Abstract

Suction gripper (10) for suctioning a workpiece (50), wherein the suction gripper (10) has: (a) a suction body (12) which defines a suction interior (20), wherein the suction interior (20) is open through a suction opening (22) of the suction body (12) and the suction body (12) has a sealing section (18) surrounding the suction opening (22) for contact with the workpiece (50) to be suctioned, (b) a connecting nipple (24) which is arranged on a first wall section (14) of the suction body (12) which limits the suction interior (20), wherein the suction body (12) is designed to be flexibly deformable such that the suction body (12) can assume a contracted configuration and an expanded configuration, wherein the suction interior (20) has a minimum volume in the contracted configuration and a maximum volume in the expanded configuration, characterized by the fact that the first wall section (14) in the contracted configuration of the suction body (12) is convexly curved towards the suction opening (22).

Description

[0001] The invention relates to a suction gripper for sucking a workpiece according to the preamble of claim 1.

[0002] Suction grippers of this type are generally used to grip a workpiece during handling using a handling device. The suction grippers have a suction body that defines a suction interior and has a suction opening. A sealing section of the suction gripper for contact with the workpiece surrounds the suction opening. The suction gripper is applied to the workpiece with the sealing section for suction. The suction gripper is connected to the handling device by means of a connection nipple arranged on the suction body. The handling device thus enables the handling of the workpiece gripped by the suction gripper. Such a suction gripper is known, for example, from DE 10 2014 218 295 A1 and DE 10 2007 045 816 A1.

[0003] In passive operation of the suction cup, the sealing section of the suction cup is placed on a surface of the workpiece and pressed down, e.g. by applying an external pressure force to the suction cup. In this case, it can be provided, for example, that some of the air in the suction chamber escapes and, when the suction body relaxes, an initial, comparatively low suction negative pressure is created in the suction chamber. Depending on the design, the air escapes, for example, laterally between the sealing section and the workpiece, or through the connection nipple. The suction cup is then lifted for handling by means of the handling device against the direction of the previously applied external pressure force. In the initially suctioned state of the suction body, the lifting causes the weight of the workpiece to act as a tensile force on the suction cup.The tensile force causes an elastic deformation of the suction body, an increase in the volume of the suction chamber and thus a further reduction of the pressure level in the suction chamber, so that finally a strong negative pressure is provided for a sufficient holding force.

[0004] During active operation of the suction gripper, the suction gripper is applied to the workpiece, and the pressure level in the suction chamber is reduced by a pump, blower, ejector, or vacuum reservoir, e.g., through a fluid channel in the connection nipple. As long as the volume flow extracted from the suction chamber in this way is kept higher than the volume flow generated by leakage between the sealing section and the workpiece, the workpiece can adhere to the suction gripper indefinitely.

[0005] The object of the invention is to provide a suction gripper with good holding properties so that the suction gripper enables more reliable handling of workpieces.

[0006] The problem is solved by a suction gripper according to claim 1. Accordingly, a suction gripper for suctioning a workpiece is proposed, wherein the suction gripper comprises: a suction body that defines a suction interior, wherein the suction interior is open through a suction opening of the suction body, and the suction body has a sealing portion surrounding the suction opening for contact with the workpiece to be suctioned. The suction body has a connection nipple arranged on a first wall portion of the suction body that defines the suction interior.In particular, in order to enable the said passive operation, the suction body is designed to be flexibly deformable such that the suction body can assume a contracted configuration and an expanded configuration, wherein the suction interior has a minimum volume in the contracted configuration and a maximum volume in the expanded configuration, wherein the first wall section in the contracted configuration of the suction body is convexly curved towards the suction opening.

[0007] If the sealing section of the suction body is placed sealingly against the surface of a workpiece and initially pressed against it, the suction body with its suction interior can be essentially sealed against the surface of the workpiece. In principle, a slight leakage from the suction interior is possible. If the suction gripper is then pulled away from the workpiece surface again using its connection nipple and / or if the workpiece pulls on the applied suction body due to its weight, this results in a flexible, and in particular elastic, deformation of the suction body from the contracted configuration towards the expanded configuration. The two aforementioned configurations can merely be understood as final configurations of the suction body, since the suction body can also assume intermediate configurations between the final configurations.

[0008] The difference in the volume of the suction chamber in the expanded configuration compared to the contracted configuration then leads to the development of a sufficiently high negative pressure, thus ensuring a particularly secure hold of the workpiece on the suction gripper. A larger difference in the volumes between the contracted configuration and the expanded configuration of the suction body promotes the development of a stronger negative pressure. For example, the volume in the expanded configuration can be five times or more the minimum volume of the suction chamber in the contracted configuration of the suction body.

[0009] In the described suction cup, the initial dead volume of the suction interior is low in the contracted state of the suction cup. This enables a high holding force and reduces the energy required to suction the workpiece during active operation. Since the wall section is convexly curved toward the suction opening in the contracted configuration of the suction body, the maximum volume of the suction interior of the suction body of the suction cup can be large, while the suction body can still be compact in the contracted configuration.

[0010] The suction body can be formed at least partially or completely from a flexible and / or elastic material, in particular from an elastomer. The suction body can, in particular, have a wall delimiting the suction opening and the suction interior, or be designed as a wall delimiting the suction opening and the suction interior. Furthermore, the suction body can have a round or oval cross-section, in particular one that is continuous along its height. This results in an suction body that has a bulbous shape in the expanded configuration.

[0011] The fact that the first wall section of the suction body in the contracted configuration of the suction body is convexly curved towards the suction opening can in particular mean that the first wall section is curved into the suction interior of the expanded configuration. In other words, when the suction opening is initially only applied to the workpiece, the first wall section curves convexly towards the workpiece. The designation of the curvature of the first wall section as concave or convex depends on the definition of the direction of the curvature and the viewing perspective. The convex curvature of the first wall section is apparent in the direction towards the suction opening, i.e. when viewing the first wall section from the workpiece, since the curvature appears convex in this case. A concave curvature of the first wall section, on the other hand, is apparent in the direction from the suction opening to the connection nipple, i.e.when viewing the first wall section from the connection nipple.

[0012] The fact that the connection nipple is arranged on the first wall section of the suction body that delimits the suction interior can mean, in particular, that the first wall section surrounds the connection nipple, in particular, is arranged so as to extend around the connection nipple. The connection nipple preferably penetrates said wall section. Accordingly, the first wall section refers, in particular, to a wall section of the suction body that extends radially away from the connection nipple. The connection nipple can be arranged at a center of the first wall section.

[0013] The first wall section and / or the connection nipple are arranged opposite the suction opening, in particular both when the suction body is in the contracted configuration and the expanded configuration. The suction gripper can be configured such that the first wall section and / or the connection nipple move away from each other during the flexible deformation from the contracted configuration toward the expanded configuration.

[0014] The connection nipple can be configured, in particular, for attaching the suction gripper to a handling device and / or for pneumatically connecting the suction interior to the environment or a vacuum supply, in particular a pump, a blower, an ejector, and / or a vacuum reservoir. Accordingly, the suction gripper can be easily handled and / or an evacuation system can be provided for active operation of the suction gripper.

[0015] Accordingly, the suction gripper can be actively operated. The connection nipple can accordingly have a fluidic connection to the suction chamber. This allows the connection nipple, when connected to the vacuum supply, to establish a vacuum connection between the suction chamber and the vacuum supply. A vacuum applied to the suction chamber causes, in particular, the suction gripper to remain in its contracted configuration, in which the volume of the suction chamber is minimal, or in an intermediate configuration with a similarly small volume. Accordingly, the suction gripper can be operated in an energy-efficient manner even in such an active mode of operation, since only a small initial dead volume needs to be evacuated.

[0016] The sealing section can be designed, in particular, as a sealing lip. The sealing lip can be configured such that it extends around the suction opening. The sealing lip can be flexible and / or elastic. The sealing lip can thus achieve an effective seal on the workpiece.

[0017] It can be provided that the first wall section, in the contracted configuration, has a convex, shell-like shape that curves toward the suction opening. This allows a particularly small minimum volume of the suction interior to be achieved in the contracted configuration of the suction body, thereby keeping energy consumption particularly low.

[0018] It can further be provided that the first wall section is designed to be flexibly deformable such that the suction body flexibly deforms during the transition from the contracted configuration to the expanded configuration. Furthermore, the first wall section can be designed to be elastically deformable. In this respect, the suction gripper changes from the contracted configuration to the expanded configuration during passive operation by flexibly deforming the first wall section, which changes its shape and position in the configurations.

[0019] For a further embodiment, it is provided that the first wall section in the expanded configuration has a shell shape that is concavely curved away from the suction opening. In this respect, the first wall section in the expanded configuration is curved opposite to the curvature in the contracted configuration. This makes it possible to achieve a particularly large maximum volume of the suction interior in the expanded configuration of the suction body. For this purpose, the first wall section can be designed to be evertable, so that the first wall section can be everted from the shell shape that is convexly curved towards the suction opening in the contracted configuration into the shell shape that is concavely curved away from the suction opening in the expanded configuration. This achieves a particularly large volume difference between the contracted configuration and the expanded configuration of the suction body.

[0020] Furthermore, the suction body can be designed such that the contracted configuration corresponds to a relaxed, non-suctioned state of the suction body. In this contracted configuration, the suction gripper can be connected to a vacuum supply, for example, via the connection nipple, and used as an actively operated suction gripper.

[0021] Furthermore, it can be provided that the absorbent body has a second wall section formed between the sealing section and the first wall section, wherein the first wall section is folded over the second wall section in the contracted configuration of the absorbent body, in particular that the first wall section rests against the second wall section in the contracted configuration of the absorbent body. This makes it possible to achieve a particularly small minimum volume of the absorbent interior of the absorbent body in the contracted configuration.

[0022] It can also be provided that the second wall section is designed as a bellows with at least one outer fold and at least one inner fold. In particular, the bellows can also be designed with at least two or more outer folds and at least two or more inner folds. The absorbent body has a smaller circumference at the inner folds and, in the case of a round cross-section, a smaller diameter than at the outer folds. By unfolding the bellows, a particularly large maximum volume of the suction interior of the absorbent body can be achieved in the expanded configuration.

[0023] It can also be provided that the second wall section, in the contracted configuration of the suction body, has a convex, curved shell shape toward the suction opening and interrupted by the suction opening. The convexity and shell shape of the second wall section toward the suction opening, which is interrupted by the suction opening, also enables a compact arrangement of the suction body together with the first wall section in the contracted configuration of the suction body, which further reduces the initial dead volume.

[0024] In particular, the second wall section can extend around the suction opening in the contracted configuration of the suction body and not be arranged above the suction opening. In other words, only the suction interior, but not the second wall section, can be located between the suction opening and the first wall section. This also enables a compact arrangement of the suction body and thus a particularly small minimum volume of the suction interior of the suction body in the contracted state.

[0025] Furthermore, it can be provided that the first wall section is connected to the second wall section by means of a fold. In other words, the suction body or a wall of the suction body is formed as a fold between the first wall section and the second wall section. During passive operation of the suction gripper, the suction body can be easily deformed along the fold from the contracted configuration toward the expanded configuration and vice versa.

[0026] It can also be provided that the second wall section is stiffer than the first wall section, at least in some regions. This enables high stability at the second wall section and high flexibility at the first wall section. The high flexibility of the first wall section can thus be used for rapid and energy-saving deformation of the first wall section to change from the contracted configuration to the expanded configuration of the suction body. In contrast, the second wall section can stabilize the suction body as a whole and, in particular, the application of the sealing section and the suction body during suction, since the sealing section, against which the workpiece rests, adjoins the second wall section.

[0027] Furthermore, it can be provided that at least one support element is arranged on a side of the first wall section facing away from the suction interior. The support element is in particular elongated, i.e. has a longitudinal extension. The longitudinal extension can be straight or curved (e.g. wavy or spiral), with the support element extending away from the connection nipple. The longitudinal extension is in particular that extension of the support element which has the greatest length. Preferably, several support elements extend radially away from the connection nipple. The support element can be arranged on the connection nipple or next to the connection nipple. Furthermore, the support element can extend up to an edge of the first wall section, in particular up to a fold between the first wall section and the second wall section.By means of the at least one support element, the first wall section can be stabilized when changing configurations.

[0028] In particular, two, three, or more support elements can be arranged on the side of the first wall section facing away from the suction chamber. This allows for better stabilization. The two, three, or more support elements can be arranged around a circumference of the connection nipple and, in particular, can be spaced equidistantly or essentially equidistantly from one another. This allows for uniform stabilization.

[0029] It can also be provided that the at least one support element is designed as a rib, which is in particular formed integrally with the suction body. Consequently, the rib can also be made of an elastomer, for example. This enables cost-effective production of the suction gripper.

[0030] Furthermore, it can be provided that the at least one support element has a material weakening such that the at least one support element is designed to be compressible and expandable along its longitudinal extent. This enables the at least one support element to compress in the contracted configuration of the suction body so that the suction interior of the suction body can occupy the smallest possible minimum volume. On the other hand, it enables the at least one support element to expand from the contracted configuration toward the expanded configuration of the suction body during passive operation of the suction gripper so that the suction interior of the suction body can occupy the largest possible maximum volume.

[0031] The material weakening comprises, in particular, a material recess, or the material weakening is formed by a material recess. The material recess can run transversely, in particular perpendicularly, to the longitudinal direction of the support element. In particular, the material recess can be designed as a slot, in particular a V-shaped slot. It is also possible for the material weakening to comprise several material recesses, for example in the form of one or more folds (in particular an expansion fold) or in the form of a bellows section.

[0032] Alternatively or additionally, it is possible to design the material weakening such that the support element is made of a material with higher compressibility and extensibility. This can, for example, be a particularly compressible and / or elastic material.

[0033] It can be provided that the material recess divides the at least one support element into at least two support element parts that can be moved relative to one another. The support element parts are moved towards one another when assuming the contracted configuration, since the first wall section collapses towards the suction opening, and are moved away from one another when assuming the expanded configuration during passive operation of the suction gripper, since the first wall section moves away from the suction opening. The at least one support element can be divided into the support element parts by means of the material recess up to the side facing away from the first wall section, so that the support element parts are connected to one another solely by means of the side facing away from the first wall section.

[0034] Furthermore, at least one of the at least two support element parts can be designed as a retrofit part. Accordingly, the opposite side of the first wall section can have at least one fastening means for fastening the at least one of the at least two support element parts. Alternatively, only the support element part can have a fastening means for fastening to the first wall section. It is also possible to glue the support element part to the first wall section. This makes it easy to increase the stability of a suction gripper while maintaining its energy efficiency and suction power.

[0035] Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which embodiments of the invention are described and explained in more detail.

[0036] They show: Fig. 1 is a cross-sectional view of an embodiment of a suction gripper in a contracted configuration; Fig. 2 a cross-sectional view of the embodiment of the suction gripper from Fig. 1 in an expanded configuration; Fig. 3 a cross-sectional view of another embodiment of a suction gripper in a contracted configuration; Fig. 4 is a cross-sectional view of yet another embodiment of a suction gripper in a contracted configuration; and Fig. 5 a cross-sectional view of yet another embodiment of a suction gripper in an expanded configuration.

[0037] Fig. Figure 1 shows a cross-sectional view of an embodiment of a suction gripper 10 in a contracted configuration. The suction gripper 10 has a suction body 12. The suction body 12 is designed to be elastic and flexible overall. For example, the suction body 12 can be made of an elastomer. The suction body 12 can also be understood as a wall in this case.

[0038] The suction body 12 defines a suction interior 20. In the contracted configuration of the suction body 12, the volume of the suction interior 20 is minimal. The suction body 12 further has a suction opening 22. The suction opening 22 is an open side of the suction body 12 and thus enables fluid communication with the suction interior 20.

[0039] The suction body 12 also has a first wall section 14, a second wall section 16, and a sealing section 18. In this case, the sealing section 18 is designed as a sealing lip. The sealing section 18 is sealingly applied to a workpiece 50.

[0040] In the contracted configuration of the suction body 12 shown, the first wall section 14 is convexly curved towards the suction opening 22, so that the first wall section 14 forms a convexly curved shell shape.

[0041] The first wall section 14 is relatively more flexible than the second wall section 16. As a result, the second wall section 16 is relatively stable, while the first wall section 14, due to its relatively high flexibility in the contracted configuration, is folded over the second wall section 16. Furthermore, the first wall section 14 is connected to the second wall section 16 by means of a fold 26 formed on the absorbent body 12. By means of the fold 26, the flexible first wall section 14 can be easily folded from the contracted state into the Fig. 2 and explained in more detail later, when the suction gripper 10 is operated passively.

[0042] In the center of the first wall section 14, a connection nipple 24 is also arranged on the suction body 12. The connection nipple 24 is enclosed in the first wall section 14 in this case. A handling device (not shown) can be connected to the connection nipple 24 to move the suction gripper 10. Once the suction gripper 10 has suctioned the workpiece 50, the workpiece 50 can also be handled via it.

[0043] Fig. 2 shows a cross-sectional view of the embodiment of the suction gripper 10 from Fig. 1 in an expanded configuration. To achieve the expanded configuration, the suction gripper 10 was placed in the contracted configuration and applied to the workpiece 50 from Fig. 1, an external initial pressure force was applied to initially press the suction interior 20 against the workpiece 50 and, if necessary, slightly secure it with suction. The suction gripper 10 was then lifted by means of the handling device.

[0044] The weight of the workpiece 50 thus leads to a flexible deformation of the suction body 12 and thus to an increase in the volume of the suction interior 20, which leads to the formation of a negative pressure in the suction interior.

[0045] The suction gripper 10 can also be active. In active operation of the suction gripper 10, in which the connection nipple 24 is connected to a vacuum supply in order to actively generate a vacuum in the suction interior 20, the suction gripper 10 remains in the contracted configuration due to the evacuation of the suction interior 20. Fig. 1. In this respect, there is generally no transition to the expanded configuration during active operation.

[0046] Fig. Figure 3 shows a cross-sectional view of another embodiment of a suction gripper 10 in a contracted configuration. In this embodiment, the second wall section 16 is designed as a bellows. In this case, the bellows has two outer folds 28.1, 28.2 and two inner folds 30.1, 30.2. In this embodiment, the second wall section 16 enables a particularly large increase in the volume of the suction interior 20 when the suction gripper 10 is transferred from the contracted configuration to the expanded configuration.

[0047] Fig. 4 shows a cross-sectional view of yet another embodiment of a suction gripper 10 in a contracted configuration. In contrast to the suction gripper 10 of Fig. 3, the outer folds 28.1, 28.2 (and the crease 26) in the contracted configuration of the suction body 12 lie on the same height plane parallel to the workpiece 50. In other words, the outer folds 28.1, 28.2 in the contracted configuration of the suction body 12 are equidistant from the workpiece 50.

[0048] In contrast, the outer folds 28.1, 28.2 (and the fold 26) in the contracted configuration of the absorbent body 12 are made of Fig. 3 in the direction from the sealing section 18 to the first wall section 14 with increasing distance from the workpiece 50. Thus, the expanding volumes of the bellows between each outer fold 28 and the associated inner fold 30 in the suction gripper 10 of the Fig. 4, while the expanding volumes between each outer fold 28 and its corresponding inner fold 30 in the suction gripper of the Fig. 3 differ from each other, namely increase in the direction from the sealing section 18 to the first wall section 14.

[0049] Fig. 5 shows a cross-sectional view of yet another embodiment of a suction gripper 10 in an expanded configuration. Three support elements 32.1, 32.2, 32.3 extend from the first wall section 14, arranged equidistantly or substantially equidistantly from one another around a circumference around the connection nipple 24. The support elements 32.1, 32.2, 32.3 stabilize the first wall section 14. Each of the support elements 32.1, 32.2, 32.3 has the same structure, with the support element 32.1 being explained in more detail for all support elements 32.1, 32.2, 32.3.

[0050] The support element 32.1 is formed as a rib integral with the first wall section 14 of the suction gripper 10. The support element 32.1 extends with its longitudinal extent from the connection nipple 24 radially to an edge of the first wall section 14. The support element 32.1 has a material weakening 36 in the form of a slot, which divides the support element 32.1 into two support element parts 34.1, 34.2 that are movable relative to one another. The material weakening 36 extends to a side of the first wall section 14 facing away from the suction interior 20.

[0051] By means of the material weakening 36, the support element 32.1 is compressible and expandable along its longitudinal extent. This allows the support elements 32.1, 32.2, 32.3 to compress despite the provided stabilization in the contracted configuration of the suction body 12, so that the suction interior 20 of the suction body 12 can occupy the smallest possible minimum volume. Furthermore, it allows the support elements 32.1, 32.2, 32.3 to expand from the contracted configuration toward the expanded configuration of the suction body 12 during passive operation of the suction gripper 10, so that the suction interior 20 of the suction body 12 can occupy the largest possible maximum volume.

Claims

[1] Suction gripper (10) for sucking a workpiece (50), the suction gripper (10) comprising: (a) a suction body (12) which delimits a suction interior (20), wherein the suction interior (20) is open through a suction opening (22) of the suction body (12) and the suction body (12) has a sealing section (18) surrounding the suction opening (22) for application to the workpiece (50) to be sucked in, (b) a connection nipple (24) which is arranged on a first wall section (14) of the suction body (12) delimiting the suction interior (20), wherein the suction body (12) is designed to be flexibly deformable such that the suction body (12) can assume a contracted configuration and an expanded configuration, wherein the suction interior (20) has a minimum volume in the contracted configuration and a maximum volume in the expanded configuration, characterized by , that the first wall section (14) is convexly curved towards the suction opening (22) in the contracted configuration of the suction body (12). [2] Suction gripper (10) according to claim 1, wherein the first wall section (14) in the contracted configuration has a shell shape which is convexly curved towards the suction opening (22). [3] Suction gripper (10) according to claim 1 or 2, wherein the first wall section (14) is designed such that it deforms flexibly during the transition from the contracted configuration to the expanded configuration. [4] Suction gripper (10) according to one of the preceding claims, wherein the first wall section (14) in the expanded configuration has a shell shape which is concavely curved away from the suction opening (22). [5] Suction gripper (10) according to one of the preceding claims, wherein the suction body (12) is designed such that the contracted configuration is assumed in a relaxed, non-suctioned state of the suction body (12). [6] Suction gripper (10) according to one of the preceding claims, wherein the suction body (12) has a second wall section (16) which is formed between the sealing section (18) and the first wall section (14), wherein the first wall section (14) is folded over the second wall section (16) in the contracted configuration of the suction body (12). [7] Suction gripper (10) according to claim 6, wherein the second wall section (16) is designed as a bellows with at least one outer fold (28.1, 28.2) and at least one inner fold (30.1, 30.2). [8] Suction gripper (10) according to claim 6 or 7, wherein the second wall section (16) in the contracted configuration of the suction body (12) has a shell shape which is convexly curved towards the suction opening (22) and interrupted by the suction opening (22). [9] Suction gripper (10) according to one of claims 6 to 8, wherein the first wall section (14) is connected to the second wall section (16) by means of a fold (26). [10] Suction gripper (10) according to one of claims 6 to 9, wherein the second wall section (16) is at least partially stiffer than the first wall section (14). [11] Suction gripper (10) according to one of the preceding claims, characterized bythat at least one support element (32.1, 32.2, 32.3) is arranged on a side of the first wall section (14) facing away from the suction interior (20), wherein the at least one support element (32.1, 32.2, 32.3) extends at least in sections in the direction away from the connection nipple (24). [12] Suction gripper (10) according to claim 11, wherein the at least one support element (32.1, 32.2, 32.3) is designed as a rib, which is in particular formed integrally with the suction body (12). [13] Suction gripper (10) according to one of claims 11 or 12, wherein the at least one support element (32.1, 32.2, 32.3) has at least one material weakening (36) such that the at least one support element (32.1, 32.2, 32.3) is designed to be compressible and expandable along its longitudinal extent. [14] Suction gripper (10) according to claim 13, wherein the material weakening (36) has at least one material recess. [15] Suction gripper (10) according to claim 14, wherein the material recess divides the at least one support element (32.1, 32.2, 32.3) into at least two support element parts (34.1, 34.2) movable relative to one another.

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