End effector and industrial robot

Abstract

The present invention relates to an end effector (10) for an industrial robot, which is adjustable between a first configuration for mechanical gripping with a first gripping device (20) and a second configuration for other gripping with a second gripping device (22). The end effector (10) has a housing (16) on the front (12) of which the second gripping device (22) is arranged. The first gripping device (20) has two gripping arms (24) mounted on the housing (16), which are configured to grip mechanically with their gripping areas in the first configuration. In the second configuration, at least one first element (26) of each of the two gripping arms (24) is arranged adjacent to the housing (16). The shape of a first partial region of each first element (26) corresponds to an outer contour of an adjacent partial region of the housing (16).Furthermore, the invention relates to an industrial robot.

Description

Technical field

[0001] The present disclosure relates to an end effector for an industrial robot. Furthermore, the present disclosure relates to an industrial robot. State of the art

[0002] Industrial robots are used to manipulate objects in industrial facilities. For example, industrial robots can pick up randomly arranged items, such as food, on a conveyor belt and place them into packaging. Industrial robots can also hold objects for joining, for example, during a welding process. Sorting tasks can also be performed by industrial robots. Industrial robots are characterized by their high flexibility and can often perform tasks that were previously reserved for humans. Other areas of application for industrial robots include medical procedures, where they can work with high precision. Such industrial robots can, for example, be used without safety barriers and in sterile environments.

[0003] An industrial robot, for example, has a base to which it is attached to a floor, and a movable support arm. The support arm can be movable in two, three, or more axes. The base can also be mounted on a cell or a pedestal. An end effector is attached to the support arm, which the robot uses to perform various tasks. Typically, the end effector must be changed depending on the task, the work step, and the object being handled. This changeover is time-consuming. Furthermore, maintaining a stock of different end effectors can be expensive. Depending on the tool or end effector, the industrial robot can perform tasks such as welding, gluing, dispersion, or additive manufacturing. Another example is product assembly.

[0004] Therefore, end effectors are also used that have multiple tools or different options for manipulating an object. Combination grippers are one example. Well-known combination grippers include the OnRobot 2FGP20, the Wegard Softgripper, the DLR Hybrid-Compliant-Gripper, and the UnisoGrip. However, these end effectors are only suitable for collaborative applications to a limited extent.

[0005] A collaborative robot can be used alongside a human in a collaborative application within a workspace. With conventional industrial robots, the potential for danger is too high for this. However, a collaborative robot can have special features, such as force limitations in the event of a collision. For example, a special external design should prevent sharp edges and corners in collaborative robots to reduce the risk of injury. Description of the invention

[0006] One key aspect concerns the end effector for an industrial robot. The robot can be configured as either an industrial robot or a lightweight robot for collaborative applications. The industrial robot can move and / or actuate the end effector attached to it. For example, the industrial robot is designed to grasp and move objects such as food. This allows it to transfer loose bulk material from a conveyor belt to defined positions within packaging. The industrial robot can also be used in assembly processes. For instance, it can grasp one component and connect it to another. The industrial robot may be equipped with sensors for its control.

[0007] The end effector can switch between a first configuration, in which it is configured for mechanical gripping with a first gripping device, and a second configuration, in which it is configured for a different gripping action with a second gripping device. The end effector can have both the first and second gripping devices. It can be designed as a combination gripper. The end effector can be configured to grip an object in two different ways. It can have two gripping devices with different gripping principles. In mechanical gripping, an object is held, for example, by friction and / or form-fit, particularly by clamping. For example, in the first configuration, the end effector can be designed as a jaw gripper. Other examples of mechanical grippers are pincer grippers and finger grippers.The first gripping device can be designed to grasp objects using an external and / or internal grip. With an external grip, the object is held securely, for example, around an outer circumference, and with an internal grip, around an inner circumference. In mechanical gripping, a pressure force is applied to the object, for example, by adjusting gripping arms. Other gripping methods can include vacuum gripping (also known as suction gripping), magnetic gripping, adhesive gripping, or other alternative gripping principles. With the second gripping device and / or other gripping methods, only one contact surface with the object is required. In contrast, the first gripping device may require two contact surfaces to grasp the object. Other gripping methods are not mechanical gripping.For example, in the second configuration, the end effector can be configured as a suction gripper, magnetic gripper, adhesive gripper (such as a gecko gripper), or an alternative gripper. The end effector can be configured to grasp objects in two different ways. In the first configuration, for example, only the first gripper can grasp objects. Alternatively, in the first configuration, the second gripper can also grasp objects alongside the first, thus supporting the first gripper. In the second configuration, for example, only the second gripper can grasp objects. The two grippers allow the end effector to be used flexibly by an industrial robot in different applications without requiring a tool change or the end effector itself.

[0008] The end effector, and the industrial robot as a whole, can be configured for collaborative applications. For this purpose, the gripping force can be limited to a maximum value. For example, the end effector can be designed for inherent force-maintaining gripping. With inherent force-maintaining gripping, no continuous actuation, such as energizing an actuator, is necessary to hold the object. A self-locking mechanism, such as a worm gear with a sufficient pitch, can be incorporated for this purpose. This ensures safe gripping even in the event of a failure. The end effector can also be designed to allow an operator to free themselves if the end effector accidentally grips a part of the operator's body. Furthermore, the end effector, and the industrial robot as a whole, can have minimal interference contours. For example, the end effector has rounded outer contours in both configurations.Sharp edges and / or shearing hazards and / or the risk of operator entrapment may be absent or minimal.

[0009] The end effector has a housing. The housing may have an interior. Actuators, sensors, control devices, and other electronic components may be arranged in and / or on the housing. The housing may be made of metal or plastic, for example. The housing may be a single piece or made of several components. For example, the housing may have two halves screwed, riveted, and / or bonded together. The two gripping devices may be attached to the housing. The housing may also form part of one or both of the gripping devices.

[0010] The second gripper is located on the front of the housing. Parts of the second gripper can also be located inside the housing. For example, a suction cup of the second gripper can protrude from the front of the housing. A gripping point or gripping area of ​​the second gripper can also be located in front of the housing. The front can be a gripping or manipulation side of the end effector. A side opposite the front can be the rear of the housing. The housing can be attached to a free end of a support arm of the industrial robot. For example, the rear of the housing can be connected to the support arm. A lateral surface of the housing can extend between the front and rear. This lateral surface can be curved in the circumferential direction. For example, the lateral surface can be circular or elliptical.The housing can, for example, have a cylindrical shape. The front surface can be flat, convex, or stepped. The rear surface can be flat, stepped, or convex. The lateral surface can extend along a longitudinal axis of the end effector.

[0011] The first gripping device has two gripping arms mounted on the housing. The gripping arms can, for example, both be mounted directly on the housing. To grip, both gripping arms are then moved. Alternatively, one of the two gripping arms can be mounted above the other. For example, the gripping arms can allow for a scissor grip. To grip, only one of the two gripping arms is moved. The two gripping arms can be identical. The two gripping arms can be evenly spaced and / or symmetrically arranged, for example, on the outer circumference of the housing. The first gripping device can also have three or more gripping arms. The following descriptions can also apply to more than two gripping arms, where applicable. The gripping arms can, for example, be articulated. The gripping arms can also be deformable.The gripping arms in this context can therefore also refer to types of gripping arms that are not articulated.

[0012] Each gripper arm can be equipped with an actuator, such as a hydraulic cylinder, a pneumatic cylinder, or an electric motor, by means of which the associated gripper arm can be moved. The electric motor can, for example, be an electromagnetic rotary motor or a linear motor. Two, more, or all gripper arms can also be moved by a common actuator. For example, each gripper arm can be mechanically connected to a motor shaft of a single actuator via a worm gear. The worm gear can be self-locking in at least one gripping position and / or a stowed position, and generally in all positions of the gripper arms of the first gripping device. In this case, no actuator force or torque is required to hold the gripper arms in position. The first gripping device can have an adjustment device. The adjustment device can be designed to move the respective gripper arms.The adjustment device can be configured to move all gripping arms uniformly and / or synchronously. The adjustment device can also be configured to move individual gripping arms independently. By moving the gripping arms, they can grasp and release an object. The configuration can also be changed by moving the gripping arms. In the first configuration, the two gripping arms are configured to grip mechanically. Gripping can be achieved, for example, using the gripping areas of the arms. These gripping areas can be located, for example, at the free ends of the gripping arms. The gripping areas of the gripping arms can be designed, for example, as jaws, pliers, or fingers.

[0013] The adjustment device can also be configured to actuate the second gripper. For example, the adjustment device can be configured to drive a pump for a second gripper designed as a suction gripper. The pump can be a vacuum pump. Alternatively, a separate actuation device can be provided for the second gripper, for example, with separate actuators. The respective actuators can be located in the housing of the end effector or in the base of the industrial robot. The gripper arms and / or their gripping areas can, for example, only be movable in a fixed plane relative to the housing. For example, the free end of each gripper arm can only be moved along a circular or elliptical path with a fixed orientation relative to the housing.

[0014] The two gripping arms are mounted, for example, on the outer surface and / or the end face of the housing. The gripping area can be located, for example, at the end of each gripping arm facing away from the housing. The first gripping device can, for example, clamp an object between the gripping areas to grasp it. The gripping areas can also press outwards from the inside against a wall in a recess of an object to grasp the object.

[0015] The gripping areas may, for example, incorporate means to increase static and / or kinetic friction with the gripped object, such as anti-slip agents. For example, the anti-slip agent may be designed as an elastomer coating. Each gripping arm may have several links. The links of a gripping arm may form a kinematic chain, in particular an open or closed kinematic chain. The first gripping device may, for example, be designed to grip objects located in front of it, for example, in a gripping area or gripping point that overlaps with the gripping point or gripping area of ​​the second gripping device. The first link may, for example, be formed in one piece or have two or more separate but jointly fixed elements.

[0016] In the second configuration, at least one first segment of each of the two gripping arms is positioned adjacent to the housing. The first segment can rest against the housing in the second configuration, be recessed, or be slightly spaced from the housing. For example, the first sections of the first segments of the gripping arms in the second configuration rest against a lateral surface of the housing that extends away from the front, particularly towards the rear. This ensures that the gripping arms are not obstructing the way when not in use. For instance, the gap between the first segment of the two gripping arms and the housing in the second configuration can be so small that a person cannot insert a finger into it.Further sections of the gripper arms, such as the second and third sections of each gripper arm (described below), can also be arranged adjacent to the housing in the second configuration. For example, additional sections can also be partially recessed into recesses in the housing in the second configuration. The first section of each gripper arm can, for instance, form the gripping area of ​​the gripper arm. The position of the first sections adjacent to the housing allows an operator to visually determine the configuration of the end effector. In the first configuration, the first sections of the gripper arms can, for example, be spaced away from the housing and / or no longer adjacent to it. This allows the operator to see how and / or what the end effector will grip. Overall, this can make collaborative applications easier and safer for the operator.

[0017] The shape of a first sub-section of each first link corresponds to an outer contour of an adjacent sub-section of the housing. In the following, the sub-sections of the housing that are adjacent to the first sub-sections of the first links in the second configuration are also referred to as adjacent sub-sections of the housing. The adjacent sub-sections of the housing can, for example, be formed by the lateral surface. For instance, the first sub-section of the first link can correspond to a rounded outer contour of the lateral surface of the housing. The first sub-section can be formed by an element of the first link. The first sub-section can, for example, form at least a partially cylindrical shape. The entire first link can also correspond in shape to the outer contour of the adjacent sub-section of the housing.

[0018] In the second configuration, additional interference contours of the end effector can be minimal, or there may even be no additional interference contours compared to the first configuration. This allows the end effector to be equally well-suited for collaborative applications in both configurations. In the second configuration, the gripper arms can be positioned to expose the first gripping device. This makes it particularly easy to visually identify that the second gripping mode is intended. Furthermore, positioning the first elements adjacent to the housing, especially its outer surface, can also facilitate visual identification of a gripping mode for operators.

[0019] In one embodiment of the end effector, the first elements can be arranged so that their first section rests against the adjacent section of the housing in the second configuration. This allows for particularly small interference contours in the second configuration, and also results in a small overall volume occupied by the end effector. For example, in the second configuration, the first elements of the gripping arms rest largely on the outer surface of the housing.

[0020] In one embodiment of the end effector, the first links in the first configuration may extend the outer contour of the housing, particularly at the front. For example, the portion of the first link whose shape corresponds to the outer contour of the housing may extend the housing in the first configuration. For example, in the first configuration, the first link may not project radially from the housing, or may project only slightly, particularly when the gripping arms' gripping areas are fully converging. This avoids additional interfering contours. The first links may project from the front of the housing in the first configuration. For example, the first links may extend a cylindrical housing shape at the front in the first configuration.The first links can be flush with the housing in the longitudinal direction of the end effector or they can have a gap. In a radial direction of both the end effector and the housing, the first links can be flush with the housing or they can form a step. The outer contour can be extended, particularly in at least one position of the gripping arms, such as when grasping objects, in the gripping position, and / or when the gripping arms are fully closed.

[0021] In one embodiment of the end effector, the first gripping device may be adjustable between a gripping position and a stowing position. The gripping position may be a position in which objects can be grasped by the first gripping device, for example, at the front. The gripping position may vary depending on the size and shape of the object to be gripped. There may also be multiple gripping positions, for example, depending on the diameter of the objects to be gripped. The first gripping device may have a plurality of gripping positions. There may also be a gripping range for the first gripping device within which the gripping areas of the gripping arms are movable. The first gripping device may have a gripping position range that is defined, for example, by possible gripping positions.The gripping position, or one of the gripping positions, can be a position in which the gripping areas of the gripping arms touch or are at least arranged as close to each other as possible. The stowed position can be a position in which gripping by the first gripping device is no longer possible, for example, at the front. For example, the housing and / or the second gripping device can block the gripping of objects by the first gripping device in the stowed position. In the stowed position, the gripping arms can be arranged adjacent to the housing, in particular as close as possible to and / or in contact with the housing. The gripping arms cannot, for example, be adjusted from the gripping position beyond the stowed position.

[0022] Moving the first gripper into its stowed position can shift the end effector into its second configuration. For example, in the stowed position, the gripper arms can release the second gripper, specifically an area for grasping objects with the second gripper. Additionally, moving the end effector into its second configuration can also activate the second gripper, such as switching on a pump for a suction gripper or an electromagnet for a magnetic gripper. However, the second gripper can also remain active at all times, for example, if it is designed as a passive adhesive gripper. In principle, the second gripper can be accessible to the first gripper or its gripper arms for grasping objects even in the stowed position. The gripping area of ​​the second gripper can be released by the gripper arms in the stowed position.

[0023] A gripping movement by the first gripping device can correspond to at least a partial path of an adjustment movement between the stowed position and the gripping position. For example, the gripping arms can be adjusted by the same actuator and / or along the same movement path as when gripping by the first gripping device if the configuration is to be changed. For example, the gripping arms can be opened to their maximum extent and / or moved apart to adjust to the second configuration. To adjust to the first configuration, the gripping arms are at least partially closed and / or moved towards each other. For external gripping in the first configuration, the gripping arms are moved further towards each other, for example, until the gripping areas are in contact with the outside of the object to be gripped and create a force-fit connection.For internal gripping in the first configuration, the gripping arms are moved away from each other until the gripping areas are in contact with the inside of the object to be gripped, creating a positive connection. Gripping can therefore be achieved, for example, by moving the gripping arms away from their stowed position (external gripping) or by moving them towards their stowed position (internal gripping; provided the gripping arms were not previously in their stowed position).

[0024] In one embodiment of the end effector, the shape of the first segment of each first link may correspond to a section of a cylinder. Alternatively or additionally, the outer contour of the housing segment adjacent to the first link, such as a section of the housing's outer surface, may correspond to a section of a cylinder. The cylinder may, for example, be a circular or elliptical cylinder. The cylindrical shape may be space-efficient, cost-effective to manufacture, and / or have minimal interference contours. For example, the segment of each first link of the gripping arms whose shape corresponds to the outer contour of the housing may have an inner contour whose shape is essentially identical to the adjacent outer contour of the housing.The outer contour of the portion of the first element of each gripper arm, which corresponds in shape to the outer contour of the housing, can also be essentially identical in shape to the outer contour of the housing or have a different shape. For example, an element of the first element of each gripper arm can be designed as a half-shell, in particular as a cylindrical half-shell, which surrounds the housing on the outside in the second configuration.

[0025] In one embodiment of the end effector, the first elements may each have a second sub-section. This second sub-section of the first elements may be configured to exert a force on the object being grasped. This allows, for example, a frictional connection to be established with the object. For instance, pressure can be applied to the object. The second sub-section may, for example, comprise the gripping area of ​​the gripping arms. The second sub-section may be formed by a second element of the first element. The housing may have recesses corresponding to these second sub-sections. The second sub-section of the first elements in the second configuration may be at least partially accommodated in these recesses.For example, at least the second section, like at least one section of the gripping area, of the gripping arms can be recessed in the second configuration. The gripping area of ​​the gripping arms may, for example, have more interfering contours than other areas due to the geometry of the objects to be gripped and / or be difficult to adapt to an outer contour of the housing. The described design can then reduce the formation of undesirable interfering contours in the second configuration. For example, the second section of the respective gripping arms can be partially recessed when the gripping arms are stowed. The recesses can, for example, be located on the front of the housing. The recess can be located adjacent to, in particular, the front and / or the outer surface.The recess can be formed, for example, in an edge between the front and the outer surface of the housing, particularly as a groove. The groove can extend from the front to the rear into the outer surface. A portion of the second gripper arm section can project from the front in the second configuration, but, for example, less far than the second gripping device. This allows the second gripping device to reduce the risk of the operator coming into unwanted contact with this portion. The projecting portion can partially or completely form the gripping area.

[0026] In one embodiment of the end effector, the two gripping arms of the first gripping device can each be movably mounted on the housing by means of a guide gear. The guide gear can define a movement path for each gripping arm when it is adjusted. The guide gear can define the movement path for gripping and / or adjusting the configuration. The guide gears of several gripping arms can be coupled to each other and / or driven by the same actuator. Then, for example, the gripping arms can always move uniformly and / or synchronously without the need for a complex control system. The defined movement path allows the gripping area of ​​each gripping arm to move, for example, along a circular or elliptical path. The movement path can extend in a plane.The planes of the movement paths of the different gripper arms can be symmetrically aligned or identical. For example, the movement path intersects a gripping point. The movement path can be partially identical to a gripping area in the first configuration. The gripping area in the first configuration can be a sub-area of ​​the movement path. The guide mechanism can define a translational movement and / or a pivoting movement of the gripper arm. The guide mechanism can be formed by individual links of the gripper arms. The guide mechanism can be designed as part of the gripper arms. The part of the guide mechanism mounted on the housing can form part of the respective gripper arm. The guide mechanism can also form part of the housing.

[0027] In one embodiment of the end effector, the gear ratio of the respective guide mechanism can change along the path of movement. Thus, the gear ratio of the guide mechanism can be variable along an adjustment movement. This allows for the optimization of the adjustment force and speed. With the same actuation force, the force acting on the gripping area of ​​the respective gripping arms can be greater when the gripping position is reached than when the stowed position is reached. For example, the guide mechanisms, and therefore the gripping arms, are driven by an actuator with constant torque and constant rotational speed. When the gripping position is reached, the force acting on the gripping area can then be greater than when the stowed position is reached. This allows the end effector to grip objects with a high force. Simultaneously, the force acting on the gripping area near the stowed position can be low.If an operator gets between the gripper arm and the housing, a small force may be exerted on them. The adjustment speed can be inversely proportional to the torque. The gear ratio of the guide mechanism can therefore result in a lower adjustment speed at the gripping area when the gripping position is reached than when the stowed position is reached. Alternatively or additionally, the gear ratio can be configured so that, with the same actuation speed, the adjustment speed of the gripping area of ​​the respective gripper arms is higher in a mid-range between the gripping and stowed positions than when the stowed position and / or gripping position are reached. For example, the guide mechanisms, and thus the gripper arms, are driven by an actuator with constant torque and constant rotational speed.This allows the gripping arms to move faster in an area between the stowed position and the gripping position. This enables particularly quick configuration changes.

[0028] In one embodiment of the end effector, the guide mechanism may comprise a first link, a second link, a third link, and a fourth link. Each link may be formed by several elements fixed together or be a single piece. For example, the links may be designed as tubes or rods. The links may form integral components of the gripping arms. The guide mechanism may, for example, be designed as a parallel crank mechanism. All respective pivot axes of the links may, for example, be arranged parallel to each other and offset. The links may be arranged in a plane. The gripping area of ​​the gripping arms may be spaced apart from the respective bearings of the links.

[0029] The first link of the guide mechanism can be formed by the first link of the gripper arm supported by the respective guide mechanism. The second link can be rotatably mounted to the first link at its first end. The third link can be rotatably mounted to the first link at its first end, spaced apart from the second link. The first end of each of the first and second links can, for example, be rotatably attached to the first link at different points. The fourth link can be formed by the housing. The second link can be rotatably mounted to the fourth link at its second end. The third link can be rotatably mounted to the fourth link at its second end, spaced apart from the second link. The second end of each of the first and second links can, for example, be rotatably attached to the fourth link at different points.The second and third links can also form parts of the gripping arm. The first end section can be opposite to the second end section. The second and third links can be designed, for example, as a rod, tube, circular bar, angled element, or other elongated and / or straight element. The edges of the links can be rounded. The guide mechanism thus designed can be compact and stable and easily provide a variable transmission. In the stowed position, the second and / or third link can be arranged adjacent to the housing, in particular adjacent to its outer surface. The second and / or third link can rest against the housing and / or be at least partially received in a recess of the housing.

[0030] The guide mechanism can have two sets of the second link and / or the third link. For example, a first set of the second and / or third link can be rotatably mounted on one side of the first link and on one side of the housing. A second set of the second and / or third link can be rotatably mounted on the opposite side of the first link and on the opposite side of the housing. The axes of rotation of the respective second links of a guide mechanism can be coaxial. The axes of rotation of the respective third links of a guide mechanism can be coaxial. The respective second links of a guide mechanism can be arranged parallel to and offset from each other. The respective third links of a guide mechanism can be arranged parallel to and offset from each other. The respective guide mechanisms can, for example, have several second links and only one third link.The respective guide mechanisms can, for example, have several third links and only one second link. The respective guide mechanisms can, for example, have several second links and several third links.

[0031] In one embodiment of the end effector, the first gripping device may be designed to grip the front of the housing. A gripping area of ​​the first gripping device and a gripping point of the second gripping device may lie on the same axis. This axis may correspond to a longitudinal extension of the end effector and / or a longitudinal axis of the housing. Similarly, the second gripping device may be designed to grip the front of the housing. Depending on the diameter of the object to be gripped, a gripping point of the first gripping device may shift along the axis. Therefore, the first gripping device is referred to as the gripping area. The second gripping device may have a static gripping point or also a gripping area that is movable along the axis. The gripping area may have multiple gripping points lying on the axis.The gripping point is also referred to as the "tool center point." By arranging both grippers on a single axis, the industrial robot can be controlled similarly or even identically in both configurations. This makes programming the industrial robot particularly easy. The axis extends, for example, orthogonally to the front of the housing. The gripping point of the second gripper can be within the gripping range of the first gripper or located at a distance from it. For a given diameter of the object to be gripped, the position of the gripping points on the axis can be identical for both grippers.

[0032] A second aspect concerns an industrial robot. The industrial robot can have a base. The base can have a housing. The base can have actuators for moving the industrial robot. The base can also have the industrial robot's control electronics. The base can be formed by a frame. The frame can be formed by rods, a worktable, or even a wall. The base can be movable, for example, by means of casters, or it can be fixed in place. The industrial robot has an end effector as described in the first aspect. Further features, embodiments, and advantages are described in the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect. The end effector can be movably mounted on the base, for example, via a support arm.The industrial robot can be designed as an articulated arm robot. The industrial robot can be designed as a robot with serial or parallel kinematics. The industrial robot can be designed as a delta robot or a hexapod. The industrial robot can be equipped for supplying power, for example with compressed air and / or electricity, and / or for actuating the end effector. Brief description of the characters Fig. Figure 1 illustrates in a schematic perspective view an end effector of an industrial robot in a first configuration in which the end effector is configured for gripping with a first mechanical gripping device, the first gripping device being shown in a maximum gripping position. Fig. Figure 2 illustrates the end effector in a schematic side view according to Fig. 1, where the first gripping device is again shown in the maximum gripping position. Fig. Figure 3 illustrates the end effector in a schematic side view according to Fig. 1, wherein the first gripping device is shown in a different gripping position, wherein a movement from the maximum gripping position in this gripping position also corresponds to part of an adjustment movement to adjust the end effector into a second configuration. Fig. Figure 4 illustrates the end effector in a further schematic side view according to Fig. 1 in the position of Fig. 3, where a housing of the end effector is partially cut out. Fig. Figure 5 illustrates the end effector in a schematic perspective view according to Fig. 1, wherein the end effector is now in a second configuration in which the end effector is configured for gripping with a second gripping device designed as a suction gripping device, wherein the first gripping device is shown in a stowed position. Fig. Figure 6 illustrates the end effector in a further schematic perspective view according to Fig. 1 in the position of Fig. 5. Fig. Figure 7 illustrates the end effector in a schematic side view according to Fig. 1 in the position of Fig. 5. Fig. Figure 8 illustrates the end effector in a further schematic perspective view according to Fig. 1 in the position of Fig. 5, where the housing of the end effector is partially cut out. Fig. Figure 9 schematically illustrates an adjustment movement and a guide gear of the end effector according to Fig. 1. Detailed description of embodiments

[0033] Fig. Figure 1 illustrates an end effector 10 for an industrial robot. Objects can be grasped by the end effector 10 at its front face 12. At its rear face 14, opposite a longitudinal axis of the end effector 10, the end effector 10 can be connected to a base of the industrial robot, for example, by a movable support arm. The end effector 10 has a housing 16, which is formed by two housing halves screwed together. The housing 16 has a cylindrical basic shape with a surface at the front 12, a surface at the rear face 14, and a circumferential surface 18 extending between them. A connecting coupling is also arranged on the rear face 14 of the housing 16, as shown in Figure 1. Fig. Figure 3 shows that in other embodiments of the end effector 10, the housing 16 has a different basic shape. The housing 16 has a flattened upper surface on its outer surface 18 for supply connections. Optionally, a corresponding lower surface is also flattened. Between the respective flattened sides, the outer surface 18 is otherwise rounded in the circumferential direction, thus contributing to the cylindrical basic shape. In another embodiment, these supply connections are covered, and the housing 16 is also cylindrical in this case. The housing 16 can also have a circular outer surface. In other embodiments, the supply connections can be partially or completely integrated into the housing or the connecting coupling.

[0034] The end effector 10 is adjustable between a first configuration in which the end effector 10 is configured for mechanical gripping with a first gripping device 20, and a second configuration in which the end effector 10 is configured for suction gripping with a second gripping device 22. In another embodiment, the second gripping device 22 is configured for a different type of gripping. Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows the end effector 10 in the first configuration. Fig. 5, Fig. 6, Fig. 7 to Fig. Figure 8 illustrates the end effector 10 in the second configuration.

[0035] The first gripping device 20 has two gripping arms 24 mounted on the housing 16. In the first configuration, the gripping arms 24 are designed to mechanically grip with their free ends, for example, to clamp an object between them. The free ends of the two gripping arms 24 form the respective gripping area of ​​each of the two gripping arms 24. Each gripping arm 24 has a first element 26, which forms the free end and thus the gripping area. The first element 26 has an end element 28 and a shell element 30, which are screwed together. The end elements 28 project forward from the shell elements 30 and form the free end with a gripping area. To grip an object, the end elements 28 press against the object from the inside or outside with the first gripping device 20, thus creating a force-fit connection to it.The shell elements 30 are designed as cylindrical half-shells, the shape of which corresponds to a basic shape of the lateral surface 18 of the housing 16, especially in the rounded area.

[0036] The gripping arms 24 are each movably mounted on the housing 16 via a guide gear, the guide gear being designed as a parallel crank gear with four links. The guide gears are particularly well suited to Fig. 8, in which one half of the casing is not shown for illustrative purposes, and are shown again in Fig. Figure 9 is shown schematically. Each guide drive has a first link 26, which is formed by the first link 26 of the gripper arm 24. Each guide drive has a fourth link, which is formed by the housing 16 in each guide drive. Each guide drive has a second link 32, which is designed as a rod. The second link 32 is rotatably mounted at one end on the first link 26 and at the opposite end on the fourth link 34 or housing 16, here close to the front 12. Each guide drive has a third link 34, which is designed as a rod. The third link 34 is rotatably mounted at one end on the first link 26 and at the opposite end on the fourth link or housing 16.The first end regions of the second link 32 and the third link 34 are each spaced apart from each other. The second end regions of the second link 32 and the third link 34 are each spaced apart from each other. Compared to the second link 32, the third link 34 is mounted further towards the rear side 14. The axes of rotation of the guide link links are arranged parallel to each other. The axes of rotation of the two guide links are arranged parallel to each other. In embodiments with three or more gripping arms 24, the axes of rotation of different guide links can be arranged at an angle to each other. In the example shown, the second links 32 and third links 34 are each rotatably mounted on the shell element 30.

[0037] In the example shown, each guide mechanism has a set of two second links 32. These second links 32 of a guide mechanism are arranged parallel to each other and have coaxial axes of rotation. The two second links 32 are arranged circumferentially at opposite end regions of the first link 26. This stabilizes the first link 26 on its planar path of motion. The third link 34 is arranged circumferentially between the two second links 32.

[0038] An actuator, not shown here, is arranged in the housing 16; this actuator may, for example, be an electric motor. The actuator is mechanically connected to the guide gear of the two gripping arms 24 via a worm gear 36, and to the third element 34, in order to synchronously drive an adjustment movement of the two gripping arms 24. The worm gears 36 are self-locking to hold the gripping arms 24 in position when the actuator is unpowered. This allows objects to continue to be held even in the event of a failure. In the illustrated embodiment, one worm gear from each worm gear 36 projects from the housing at the outer surface 18. In other embodiments, the worm gears are completely enclosed within the housing 16.

[0039] The second gripping device 22 has a suction cup 38 which projects from the front 12 of the housing 16. The suction cup can be designed as a bellows or a flat suction cup. A vacuum can be generated at the suction cup 38 by means of an associated pump in order to grip objects located in front of the suction cup 38. In one embodiment, the pump can be driven by the actuator for the gripping arms 24, and in another embodiment, it can be operated separately.

[0040] As can be seen, the gripping arms 24 cover the suction cup 38 from the front in the first configuration of the end effector. The suction cup 38 cannot thus come into smooth contact with a gripping object, or at least not without sufficient clearance from the gripping arms 24. The second gripping device 22 is not used in the first configuration, or only to support the first gripping device 20.

[0041] Fig. 1 and Fig. Figure 2 shows the gripping arms 24 in a maximum gripping position, in which the free ends of the end elements 28 are in contact with each other. In this position, the first links 26 with the shell elements 30 extend the outer surface 18 of the housing 16 at the front. The shell elements 30 do not project radially, at least in the cylindrical area of ​​the outer surface 18. In the longitudinal direction, the shell elements 30 are flush or almost flush with the outer surface 18. This avoids interfering contours in collaborative applications. Furthermore, it is clearly visible to an operator that the end effector 10 is operating in its first configuration.

[0042] To grip an object from the inside, the gripping arms 24 are moved apart at their free ends along the path of movement defined by the guide gears. A corresponding position is in Fig. 3 and Fig. Figure 4 illustrates this. The free ends of the gripping arms 24 move along the longitudinal axis towards the rear 14 and thus towards the housing 16. In addition, the free ends of the gripping arms 24 are moved radially apart. For example, to grip an object from the outside, the gripping arms 24 are moved from this gripping position towards each other and thus in the direction of the position of Fig. 1 and Fig. 2 moved to clamp the object between the free ends of the end elements 28 from the outside.

[0043] To adjust the end effector 10 to its second configuration, the two gripping arms 24 are pivoted further towards the rear 14. From a maximum open position, in which the free ends of the gripping arms 24, and thus also the end elements 28, are at their maximum radial distance, the free ends, and thus also the end elements 28, move radially inwards again, and thus radially towards the housing 16. The free ends of the gripping arms 24 are therefore movable along a curve, for example, a part of a circular path.

[0044] When a final position is reached, the shell elements 30 and / or the end elements 28 are arranged adjacent to the housing 16 on the outside, for example, at least partially abutting it. Such a position is described in the Fig. 5, Fig. 6 to Fig. Figure 7 shows the gripping arms 24 in their stowed position. The suction cup 38 is arranged radially between and along the longitudinal axis, in front of the free ends of the gripping arms 24. This prevents the gripping arms 24 from grasping objects, and the end effector 10 is in the second configuration, in which objects can be grasped, for example, only with the second gripping device 22 by means of a vacuum in the suction cup 38.

[0045] Accordingly, in the second configuration, the first element 26 of the two gripping arms 24 is arranged adjacent to the housing 16, particularly in the radial direction. As can be seen, the shape of a first sub-area of ​​the first element 26, formed by the shell elements 30, corresponds to an outer contour of an adjacent sub-area of ​​the housing 16, which here is formed by the outer surface 18. In the second configuration, the first elements 26 either abut the adjacent sub-area of ​​the housing 16 or are spaced apart from it by a small gap. The end elements 28 project radially inward from the shell elements 30. The housing 16 has a groove-shaped recess 40 at an edge between the outer surface 18 and the front face 12, in which the end elements 28 are partially received in the stowed position.The first links 26 each have a second sub-section formed by the end elements 28, the second sub-section of the first links 26 being designed to establish a frictional and / or positive locking connection with the object to be gripped. The housing 16 thus has corresponding recesses 40 for the second sub-sections, in which the second sub-section of the first links 26 is at least partially received in the second configuration and thus also in the stowed position of the gripping arms 24. Likewise, a bearing area, in which the third links 36 are rotatably attached to the shell element 30, as well as the third links 34 themselves, are at least partially received in a corresponding recess 42 of the housing 16 in the area of ​​the outer surface 18. The second links 32 are arranged adjacent to a flat side between the two cylindrical parts of the outer surface 18.The shell elements 30 thus at least partially conceal the second elements 32. This results in a compact second configuration with minimal interference contours.

[0046] The first gripping device 20 is thus adjustable between various gripping positions and the stowed position. A gripping movement by the first gripping device 20 corresponds to at least a partial movement of an adjustment between the stowed position and the gripping position. Adjusting the first gripping device 20 to the stowed position adjusts the end effector 10 to the second configuration. The gripping area of ​​the second gripping device 22 in front of the suction cup 38 is released by the gripping arms 24 in the stowed position.

[0047] Fig. Figure 9 schematically illustrates, using a simplified representation of an end effector 10, the movement path of the first link 26 at a free end of the first link 26 projecting maximally radially inwards. The movement path is represented by a circle 44. A gripping area of ​​this free end of the first link 26, and thus of the gripping arms 24, in which the mechanical gripping takes place in the first configuration, is marked by area 52. As can be seen, a gripping point moves along a gripping axis, depending on the thickness of a gripping area of ​​the object, and thus along an axis corresponding to the longitudinal extent of the end effector 10 between the front 10 and the back 12. This axis is represented by line 46 in Fig.9. Furthermore, the free ends of the gripping arms 24 move radially towards and away from each other along this gripping area. A gripping point of the second gripping device 22 also lies on the axis marked by line 46, which here corresponds to a point directly on an axis of symmetry of the suction cup 38, located in front of the suction cup 38. The gripping area of ​​the first gripping device 20 and the gripping point of the second gripping device 22 thus lie on the same axis marked by line 46. Due to the symmetrical and synchronous movement of the two gripping arms 24, the gripping point of the first gripping device 20 shifts only along the axis marked by line 46. An object to be gripped is therefore grasped in such a way that the distance of the object surfaces to the axis 46 marked by line 46 is each half of a local object thickness.An imaginary center point of the two gripping arms 24 shifts over the movement range only along the axis marked by line 46, but not in any other spatial direction.

[0048] The gear ratio of the respective guide mechanism changes along the path of movement of the free ends, and thus of the first link 26, the gripping arms 24, for example, according to the relative lever arms of the second links 32 and third links 34. A force acting on the free end of the respective gripping arms 24 is greater when the gripping position is reached than in an intermediate range between the gripping position and the stowed position and / or when the stowed position is reached. Alternatively or additionally, the adjustment speed of the free end of the respective gripping arms 24 is greater when the gripping position is reached quickly and forcefully in the intermediate range between the gripping position and the stowed position than when the stowed position and / or when the gripping position is reached. Reference sign 10 End effector 12 Front 14 Back 16 Housing / fourth link 18 lateral surface area 20 First gripping device 22 Second gripping device 24 gripper arms 26 First item 28 End element 30 shell elements 32 Second part 34 Third member 36 worm gears 38 vacuum cleaners 40 Exclusion 42 Exclusion 44 Circle / Movement path of the free end of the gripper arms 46 Line / Axis 52 Gripping range of the first gripping device

Claims

End effector (10) for an industrial robot, wherein the end effector (10) is adjustable between a first configuration in which the end effector (10) is configured for mechanical gripping with a first gripping device (20) and a second configuration in which the end effector is configured for other gripping with a second gripping device (22), wherein the end effector (10) has a housing (16), wherein the second gripping device (22) is arranged on a front face (12) of the housing (16), wherein the first gripping device (20) has two gripping arms (24) mounted on the housing (16), which are configured to grip mechanically with their gripping areas in the first configuration.wherein at least one first element (26) of the two gripping arms (24) in the second configuration is arranged adjacent to the housing (16) and wherein a shape of a first sub-area of ​​the respective first element (26) corresponds to an outer contour of an adjacent sub-area of ​​the housing (16). End effector (10) according to claim 1, wherein the first elements (26) each bear against the adjacent part of the housing (16) in the second configuration (22) with the first part. End effector (10) according to claim 1 or 2, wherein the first links (26) in the first configuration extend the outer contour of the housing (16), in particular at the front (12). End effector (10) according to one of the preceding claims, wherein the first gripping device (20) is adjustable between a gripping position and a stow position, wherein adjusting the first gripping device (20) into the stow position adjusts the end effector (10) into the second configuration, in particular wherein a gripping area of ​​the second gripping device (22) is released by the gripping arms (24) in the stow position and / or wherein a gripping movement by the first gripping device (20) corresponds to at least a partial path of an adjustment movement between the stow position and the gripping position. End effector (10) according to one of the preceding claims, wherein the shape of the first part of the first member (26) corresponds to a part of a cylinder and / or wherein the outer contour of the part of the housing (16) adjacent to the first member (26) corresponds to a part of a cylinder. End effector (10) according to one of the preceding claims, wherein the first links (26) each have a second sub-area, in particular wherein the second sub-area of ​​the first links (26) is designed to exert a force on the object to be gripped when gripping, and wherein the housing (16) has recesses (40) corresponding to the second sub-areas in which the second sub-area of ​​the first links (26) is at least partially received in the second configuration. End effector (10) according to one of the preceding claims, wherein the two gripping arms (24) of the first gripping device (20) are each movably mounted on the housing (16) by means of a guide gear, wherein the guide gear specifies a movement path (44) for the respective gripping arm (24) when it is adjusted. End effector according to claim 7, wherein a translation of the respective guide gear changes along the path of motion (44), in particular wherein a force acting on the gripping area of ​​the respective gripping arms (24) is greater when the gripping position is reached than when the stow position is reached, when actuated with the same force, and / or wherein an adjustment speed of the gripping area of ​​the respective gripping arms (24) is greater when actuated quickly and strongly in an intermediate area between the gripping position and the stow position than when the stow position is reached and / or when the gripping position is reached. End effector (10) according to claim 7 or 8, wherein the respective guide mechanism comprises a first link (26), a second link (32), a third link (34) and a fourth link (16), wherein the first link (26) of the guide mechanism is formed by the first link (26) of the gripper arm (24) supported by the respective guide mechanism, wherein the second link (32) is rotatably mounted on the first link (26) with a first end region, wherein the third link (34) is rotatably mounted on the first link (26) with a first end region rotatably spaced apart from the second link (32), wherein the fourth link (16) is formed by the housing (16), wherein the second link (32) is rotatably mounted on the fourth link (16) with a second end region, and wherein the third link (34) is rotatably spaced apart from the second link with a second end region (32) is located on the fourth member (16). End effector according to one of the preceding claims, wherein the first gripping device (20) is designed for gripping in front of the front (12) of the housing (16), wherein a gripping area (52) of the first gripping device (20) and a gripping point of the second gripping device (22) lie on the same axis (46). Industrial robot with an end effector (10) according to one of the preceding claims.

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