Protective device for a handling device

Abstract

The invention relates to a protective device (10) for detecting a collision of a handling module (102) for a handling device (104), in particular for an industrial robot or a driverless transport device, on which the handling module (102), in particular a gripping module, can be arranged, wherein the protective device (10) is connected directly or indirectly to the handling module (102), wherein the protective device (10) has at least one base plate (12, 16) and at least one counter plate (14, 18) that can be brought into contact with the base plate (12, 16), wherein the base plate (12, 16) and the counter plate (14, 18) are braced against one another by means of a pretensioning element (20) and the counter plate (14, 18) is movably mounted on the base plate (12, 16) against the force of the pretensioning element (20), and wherein the counter plate (14, 18) is movable by means of at least one with the counter plate (14,18) is guided by a positively cooperating guide means (22), and wherein at least one sensor (24) is included for detecting a spacing of the counterplate (14, 18) from the base plate (12, 16). Furthermore, the invention relates to a handling system with a protective device according to the invention.

Description

[0001] The invention relates to a protective device for detecting a collision of a handling module for a handling device on which the handling module can be arranged, and wherein the protective device is directly or indirectly connected to the handling module. Furthermore, the invention relates to a handling system comprising a protective device according to the invention, a handling device, and a handling module.

[0002] Known handling devices, such as industrial robots or automated guided vehicles, often have an interchangeable handling module, for example a gripper, that can be attached to the handling device. The handling module can be moved and controlled by the handling device. For example, external intervention in the working space of the handling device or unplanned incorrect control of the handling device can lead to a collision between the handling module and another object or a person. In particular, if such a collision is not detected promptly, this can lead to personal injury, damage to objects in the surrounding area, and / or damage to the handling module or the handling device itself.Typically, the handling device can only be shut down in the event of a collision by the overload protection of the handling device's axis drives. However, this can neither reliably prevent the aforementioned damage nor minimize consequential damage. For example, DE 41 31 602 A1 teaches a gripper mount with which the gripper is suspended at the end of a mounting arm and can therefore deflect in the event of an unforeseen or excessive load. US 2008 / 0289705 A1 discloses a protective device for monitoring the deflection of an end effector.

[0003] It is also known to monitor the working space of such handling devices in order to detect any intrusion into the working space of the handling device. For this purpose, movable protective devices, such as safety doors, flaps, or non-separating protective devices, such as laser scanners or safety mats, are known. These can detect, for example, access by operating personnel to the working space of the handling device during active operation of the handling device and trigger a corresponding signal that, for example, stops the movement of the handling device. However, such monitoring of the entire working space of the handling device is extremely complex and focused on the intervention of operating personnel in the working space, while other types of collision of a handling module are not detected. In addition, the installation of such protective devices involves considerable costs and setup effort.

[0004] The invention is therefore based on the object of providing a protective device for the operation of a handling device with a handling module, in particular one that is freely movable in space, which enables the safe operation of such a handling device with a handling module without complex peripheral devices and reliably protects against damage to people, objects, and the handling module. Furthermore, the planning and manufacturing costs, space requirements, and commissioning effort are to be minimized.

[0005] This object is achieved by a protective device having the features of claim 1. The protective device according to the invention, which is designed to detect a collision of a movable handling module for a handling device, can be connected directly or indirectly to the handling module of the handling device. In other words, the protective device is suitable for arrangement on a handling device and can serve to detect a collision of a handling module arranged on the handling device, such as a gripping module. Within the scope of the invention, the handling device can be designed as an industrial robot or driverless transport device. The handling module attachable to the handling device can be freely movable in space by means of the handling device.A handling module is also known as an "end effector" and can form the final element in the kinematic chain of a handling device, such as an industrial robot. If the handling module is designed as a gripping module, it can at least grasp and hold objects.

[0006] The protective device according to the invention is characterized in that the protective device has two pretensioning elements, two base plates and two counter plates, wherein each counter plate can be brought into contact with a base plate, wherein the base plates are arranged at right angles to one another, wherein the base plates and the counter plates are braced against one another by means of the pretensioning elements, and wherein the counter plate is movably mounted on the base plate against the force of the pretensioning element, and wherein the counter plate is guided by means of at least one guide means which interacts positively with the counter plate, and wherein at least one sensor is included for detecting a spacing of the counter plate from the base plate.

[0007] The protective device comprises a pressure sensor and a fluid channel for a pressurized fluid, wherein at least a portion of the fluid channel is incorporated into the counterplate and / or the baseplate such that the baseplate and the counterplate come into contact with the fluid, and wherein the pressure sensor is connected to the fluid channel to detect a pressure drop in the fluid channel. Thus, in the event of a pressure drop in the fluid channel, the pressure sensor can detect a separation of the counterplate from the baseplate.

[0008] Accordingly, the invention is based on the fundamental idea that if the handling module collides, for example with another object, the counterplate is moved away from the base plate against the force of the preload element, and this movement is detected by a sensor. As a result of the detection of a movement, an alarm or an immediate stop of the handling device can be triggered, for example. Due to the preload of the counterplate by means of the preload element and the guide means that interacts positively with the counterplate, the counterplate can be brought back into contact with the base plate after a collision due to the force of the preload element.In addition to returning the counterplate to a normal state, namely the full-surface contact of the counterplate with the baseplate, the preload element enables the adjustment of the force required to distance the counterplate from the baseplate in the event of a collision. In other words, the stronger the preload between the baseplate and counterplate, the stronger the collision force required to cause the baseplate to distance itself from the counterplate. The preload element can be designed as a spring or elastomer. More preferably, the preload element is designed as a tension spring or compression spring. The counterplate is preferably circular disk-shaped. The baseplate is preferably at least partially complementary to the counterplate.

[0009] Since two base plates are arranged at right angles to one another, monitoring of the handling module is possible in all three coordinate axes (X, Y and Z axes). This also allows all twists and tilts to be reliably detected. The base plates can be rigidly connected to one another. The base plates can be connected, for example, via a screw connection. It will be understood by a person skilled in the art that a counter plate can be brought into contact with each of the base plates and that each counter plate is preloaded against a base plate by a respective preload element. If the base plates are arranged at right angles to one another, the counter plates and / or preload elements connected to the base plates can also be arranged at right angles to one another, at least in the normal state of the protective device.

[0010] In the context of the invention, the term spacing of the counter plate from the base plate does not only refer to a full-surface spacing of the counter plate from the base plate, but rather also includes a tilting of the counter plate relative to the base plate.

[0011] By means of the pressure sensor, even minimal spacings between the counterplate and the baseplate can be detected. Spacings between the edge of the counterplate and the baseplate that are less than 0.2 mm can be detected. Preferably, spacings between the edge of the counterplate and the baseplate that are less than or equal to 0.1 mm can be detected. The fluid channel can be completely incorporated into the baseplate and / or counterplate. The pressure sensor is preferably designed as a pressure switch. In the context of the invention, a pressure switch is a mechanical or electronic switch that is actuated when the pressure of a gaseous or liquid medium changes. The fluid channel is preferably designed as an air channel, i.e. for conducting compressed air. The pressure of the fluid can be less than 2 bar, preferably less than 1.2 bar, more preferably 1 bar.To regulate the pressure of the fluid, the protective device can have a pressure control device, for example a pressure reducer. To regulate the volume flow of the fluid, the protective device can have a volume flow control device, for example a volume flow throttle. The volume flow of the fluid can be 0.5 liters per minute to 3 liters per minute (l / min), preferably 0.75 l / min to 2 l / min and more preferably 1 l / min to 1.5 l / min. Preferably, the pressure is reduced and the volume flow throttled. In the context of the invention, the term fluid channel refers to a channel that is suitable for conducting a fluid, in particular for conducting compressed air. The fluid channel can be introduced directly into the counterplate and / or baseplate. Alternatively or additionally, the fluid channel can be formed at least in sections by a fluid hose. The fluid hose can be arranged inside or outside the counterplate and / or the baseplate.

[0012] By means of the sensor, the transition from a normal state of the protective device to a collision state can be detected, wherein in a normal state of the protective device the base plate rests against the counter plate and in a collision state of the protective device the counter plate is spaced from the base plate.

[0013] The fluid channel can be incorporated into the base plate in such a way that the fluid channel ends at the counterplate. In other words, the fluid channel is incorporated into the base plate in such a way that the counterplate closes an opening of the fluid channel when the counterplate is in contact with the base plate. Thus, it is advantageously only necessary to insert the channel into the base plate, which can significantly reduce manufacturing and assembly costs, particularly the effort required to align the base plate with the counterplate.

[0014] The fluid channel can be branched, so that at least two branches of the fluid channel can end at the counterplate. It is understandable that the more branches of the fluid channel end at the counterplate, the more reliably the detection of a distance between the counterplate and the baseplate is possible. In particular, a tilting of the counterplate relative to the baseplate due to a collision can be detected with increased reliability by a fluid channel having multiple, in particular at least two, branches.

[0015] The protective device can comprise at least three guide means which pass through the base plate and at least engage with the counter-plate. The guide means can be designed as pins. According to a preferred embodiment, the pins do not pass completely through the counter-plate in the normal state, but are inserted into the counter-plate, in particular into openings in the counter-plate. The longitudinal axis of the guide means can run parallel to the direction of force of the prestressing element, for example a longitudinal axis of a tension or compression spring. The guide means serve to guide the counter-plate during a movement of the counter-plate relative to the base plate when the protective device is transferred into a collision state and / or when the counter-plate is returned to the base plate in order to transfer the protective device from a collision state to a normal state.The guide means can be arranged along the outer circumference of the counterplate and evenly spaced from one another. Preferably, six guide means, particularly designed as pins, are provided, which are arranged evenly spaced along the outer circumference of the counterplate.

[0016] At least three guide recesses can be incorporated into the counterplate, each of which can interact positively with a guide means. The guide recesses can be designed as elongated holes. The number of guide recesses preferably corresponds to the number of guide means.

[0017] Six guide recesses can be provided, which interact with six guide means in a form-fitting manner in order to reliably guide a movement of the counterplate relative to the base plate. If a plurality of guide means are each guided in a guide recess, wherein the guide recesses are designed as elongated holes, tilting of the counterplate relative to the base plate can be detected and, at the same time, reliable guidance of the movement of the counterplate back to the base plate can be ensured. Advantageously, at least three guide means can each be guided in a guide recess. The width of the elongated holes can preferably be complementary to the diameter of the guide means, in particular of a guide means designed as a pin.

[0018] It is known that a manufacturing-related play can arise between a guide recess which is intended to interact positively with a guide means, and this play should generally be kept to a minimum, particularly in devices of this type. However, within the scope of the invention it was recognized that a play between the guide means and the guide recess is indeed advantageous in order to allow tilting of the counter plate relative to the base plate. In other words, it has proven advantageous within the scope of the invention if the guide recesses are slightly wider than the guide means, in particular if the width of the guide recesses is slightly larger than the diameter of a guide means designed as a pin. A play fit can be formed between the guide means and the guide recess.

[0019] The guide recesses can intersect the edge of the counterplate and / or be evenly distributed along the outer circumference of the counterplate. The guide recesses can be designed as an elongated hole that is open on one side and whose open end is arranged at the edge of the counterplate. Thus, if the counterplate is designed in the shape of a circular disk, the open elongated hole extends from the edge of the counterplate towards the center of the counterplate. If the guide recesses, which can be designed as elongated holes, are evenly distributed, the longitudinal axes of the elongated holes can intersect in the center of the counterplate that is designed in the shape of a circular disk. In the context of the invention, the term “elongated hole that is open on one side” refers to an elongated hole that is only delimited by a wall on one side with regard to its longitudinal extent, i.e. along the longitudinal axis.

[0020] The prestressing element can be arranged on a fastening element for easy application of the prestress, wherein the fastening element can be connected to the counterplate by at least one fastening means. The fastening element can be plate-shaped. The base plate can be arranged between the fastening element and the counterplate for bracing the counterplate, wherein the fastening means can penetrate the base plate. The prestressing can be easily adjusted by adjusting the spacing of the fastening element from the base plate and thus also the spacing of the fastening element from the counterplate. The fastening means can be designed as a screw that interacts with the counterplate and / or base plate. Preferably, two fastening means can be provided.The fastening means may have a thread which cooperates with a nut on the counter-plate or an internal thread introduced into the counter-plate in order to be able to adjust the spacing of the fastening element relative to the counter-plate and to ensure the desired spacing between the counter-plate and the fastening element.

[0021] The preload element can be designed as a compression or tension spring. The preload element can also pass through the counterplate and / or the base plate. Preferably, the preload element passes through the base plate and comes into contact with the counterplate. For the most efficient and directed application of force, the preload element can be attached to the fastening element and the counterplate. In order to make the contact surface of the counterplate on the base plate as large as possible, the opening in the base plate through which the preload element passes through the base plate can be designed to complement the external geometry of the preload element. This means that if the preload element is designed as a cylindrical tension or compression spring, the opening in the base plate can be circular to complement the diameter of the tension or compression spring.

[0022] The protective device can comprise a transmission device that transmits data from the sensor. The data can at least comprise measured values ​​from the sensor. However, it is also conceivable for the protective device to have an evaluation device that evaluates the measured values ​​from the sensor, so that the transmission device transmits data regarding the state of the protective device, in particular whether it is in the normal state or in the collision state. It is also conceivable for the transmission device to only transmit data if a change in state occurs, for example from a normal state to a collision state of the protective device. The transmission device can transmit data to the control device of the handling device on which the handling module to be monitored is arranged.Based on the transmitted data, a corresponding response can be triggered by the control device of the handling device, such as bringing the handling device to a standstill and / or issuing an alarm signal. Data transmission via the transmission device can be wireless and / or wired.

[0023] Advantageously, a single sensor can be included to detect the spacing between the counterplate and the baseplate, by means of which both the spacing of the first counterplate from the first baseplate and the spacing of the second counterplate from the second baseplate can be detected. If the sensor is designed as a pressure sensor, the fluid channel can preferably be branched such that at least one branch leads to the first counterplate and at least one branch leads to the second counterplate, and a pressure drop between the compressed air supply to the counterplate and the first branch within the counterplate is detected by means of a single sensor.

[0024] The invention further relates to a handling system comprising a protective device according to the invention, a handling device, and a handling module. The handling module, which can be designed as a gripping module, can be arranged on a first counterplate, and the handling device, which can be designed, for example, as an industrial robot, can be arranged on a second counterplate of the protective device.

[0025] It is understood that the statements made regarding the protective device relate equivalently to the handling system according to the invention, without being specifically mentioned for this purpose. In particular, it is understood that customary linguistic transformations and / or analogous replacement of respective terms within the scope of common linguistic practice, in particular synonyms supported by generally accepted linguistic literature, are encompassed by the present disclosure content without being explicitly mentioned in their respective formulation. The scope of the invention includes all combinations of at least two features disclosed in the description, the claims, and / or the figures.

[0026] The invention is explained in more detail below with reference to the drawings.

[0027] They show: Fig. 1 shows a protective device according to the invention with a handling module arranged on the protective device in a first isometric view; Fig. 2 the protective device with the handling module arranged thereon in accordance with Fig. 1 in a second isometric view; Fig. 3 the protective device according to Fig. 1 in top view without handling module; Fig. 4 the protective device according to Fig. 3 in front view; Fig. 5 the protective device according to Fig. 3 in side view; Fig. 6 a handling system according to the invention in a side view.

[0028] The Fig. 1 shows a protective device according to the invention, on the first counter plate 14 of which a handling module 102 designed as a gripping module having two gripping jaws 106 is arranged. A summary of the Fig. 1 with the Fig. 2 to 5, the inventive structure and the inventive mode of operation of the protective device 10 can be seen. The protective device 10 is designed to detect a collision of the handling module 102, which is freely movable in space, with an object or a person according to the Fig. The embodiment shown in Figures 1 to 5 is constructed from two base plates 12, 16 arranged at right angles to one another and two counter plates 14, 18 that are movable relative to the base plates 12, 16. In each of the figures, the protective device 10 is shown in its normal state. In the event of a collision, at least one of the counter plates 14, 18 is moved relative to one of the base plates 12, 16, so that at least one of the counter plates 14, 18 is spaced apart from one of the base plates 12, 16. In particular, in the present exemplary embodiment, the spacing of the first counter plate 14 from the first base plate 12 and the spacing of the second counter plate 18 from the second base plate 16 can be detected. The first base plate 12 is fixed at a right angle to the second base plate 16 by means of the connecting screws 42. The first counter plate 14 is arranged on the first base plate 12 via the plate-shaped fastening element 34 and the fastening means 36.The fastening means 36 extend through the fastening element 34, the first base plate 12, and the first counterplate 14. The fastening means 36 can, as shown here, comprise a screw and a nut that interacts with the screw. The second counterplate 18 is also arranged in the same way with a plate-shaped fastening element 34 and fastening means 36 on the second base plate 16. In particular, the . Fig. 3 shows that the movement of the first counterplate 14 relative to the first base plate 12 and the movement of the second counterplate 18 relative to the second base plate 16 is each guided by means of six guide means 22. The guide means 22 extend through the base plate 12 or the base plate 16 and engage in the counterplate 14 or the counterplate 18 without completely penetrating the respective counterplate 14, 18. For guidance, the guide means 22 engage in guide recesses 30, which, according to the embodiment shown, are designed as elongated holes. The guide recesses 30 are each arranged evenly along the circumference of the circular disk-shaped counterplates 14, 18. This means that the longitudinal axes of the guide recesses 30 designed as elongated holes intersect at the center of the respective counterplate 14, 18 and two longitudinal axes of the guide recesses 30 each enclose an angle of 60°.The guide recesses 30 intersect the edge 32 of the respective counterplate 14, 18 into which they are inserted, so that the guide recesses 30, according to the illustrated embodiment, are designed as an elongated hole open on one side. To detect a collision in which one of the counterplates 14, 18 is spaced apart from one of the base plates 12, 16, the protective device 10 has a branched fluid channel 26 into which compressed air can be introduced, as well as a pressure sensor 24. In the normal state, compressed air is introduced into the branched fluid channel 26 via the compressed air connection 40, with the compressed air in the fluid channel 26 being at a pressure of approximately 1 bar.If there is even a slight spacing of one of the counter plates 14, 18 from one of the base plates 12, 16, for example by tilting one of the counter plates 14, 18 relative to one of the base plates 12, 16, the pressure in the fluid channel 26 drops due to a compressed air outlet at one of the test points 44, wherein the pressure drop is detected by the pressure sensor 24. In particular the . Fig. 3 and Fig. 4 it can be seen that the test points 44 are the points at which the fluid channel 26 exits one of the base plates 12, 16 and passes into one of the counter plates 14, 18 or is the point at which the fluid channel 26 ends at one of the counter plates 14, 18. As can be seen in particular from the Fig. 3 and Fig. 4, the protective device 10 according to the illustrated embodiment has a total of four test points 44, two of which are arranged on the contact surface between the first base plate 12 and the first counter-plate 14 and two further test points 44 on the contact surface between the second base plate 16 and the second counter-plate 18. The test points 44 each form the end of a branch 28 of the fluid channel 26. Advantageously, the branches 28 of the fluid channel 26 converge in such a way that the measurement of a pressure drop in one of the branches 28 of the fluid channel 26 is possible using a single pressure sensor 24. For this purpose, the pressure sensor 24 is arranged between the compressed air connection 40 and a first branch 46 of the fluid channel 26.

[0029] Fig.6 shows a handling system 100 according to the invention with a handling module 102, a handling device 104, and a protective device 10 according to the invention. The protective device is arranged between the handling device 104, which is designed as an industrial robot, and the handling module 102, which is designed as a gripping module. The second counterplate 18 is rigidly connected to the handling device 104 via the connecting piece 38 (not visible here). The handling module 102, which has gripping jaws 106, is rigidly connected to the counterplate 14 of the protective device 10, so that in the event of a collision between the handling module 102 and / or the handling device 104 and a person or an object, one of the counterplates 14, 18 can be spaced apart from one of the base plates 12, 16, with the pressure sensor 24 of the protective device 10 detecting the spacing via a pressure drop.As a result of the transmission of the data of the pressure sensor 24 to a control device of the handling device 104 (not shown here), a standstill of the handling device 104 and / or the output of an alarm signal can be triggered.

Claims

[1] Protective device (10) for detecting a collision of a handling module (102) for a handling device (104), in particular for an industrial robot or a driverless transport device, on which the handling module (102), in particular a gripping module, can be arranged, wherein the protective device (10) is directly or indirectly connected to the handling module (102), characterized by , that the protective device (10) has two base plates (12, 16), two counter plates (14, 18) and two pretensioning elements (20), wherein one of the two counter plates (14, 18) can be brought into contact with one of the two base plates (12, 16), wherein the base plates (12, 16) are arranged at right angles to each other, and wherein the base plate (12, 16) and the counter plate (14, 18) are clamped against each other by means of the pretensioning elements (20) and the counter plate (14, 18) is movably mounted on the base plate (12, 16) against the force of the pretensioning element (20), and wherein the counter plate (14, 18) is guided by means of at least one guide means (22) which cooperates positively with the counter plate (14, 18), and wherein at least one pressure sensor (24) and one fluid channel (26) for a pressurized fluid for detecting a spacing of the counter-plate (14, 18) from the base plate (12, 16) are included, wherein at least a portion of the fluid channel (26) is introduced into the counter plates (14, 18) and / or the base plates (12, 16) in such a way that the base plates (12, 16) and the counter plates (14, 18) come into contact with the fluid, and wherein the pressure sensor (24) is connected to the fluid channel (26) for detecting a pressure drop in the fluid channel (26). [2] Protective device according to claim 1, characterized by that in a normal state of the protective device (10) the base plate (12, 16) rests against the counter plate (14, 18), and in a collision state of the protective device (10) the counter plate (14, 18) is spaced from the base plate (12, 16). [3] Protective device according to claim 1 or 2, characterized by that the fluid channel (26) is introduced into the base plate (12, 16) and ends at the counter plate (14, 18). [4] Protective device according to one of claims 1 to 3, characterized by that the fluid channel (26) is branched and at least two branches (28) of the fluid channel (26) end at the counter plate (14, 18). [5] Protective device according to one of claims 1 to 4, characterized by that at least three guide means (22), in particular pins, are included, which pass through the base plate (12, 16) and engage in the counter plate (14, 18). [6] Protective device according to claim 5, characterized bythat at least three guide recesses (30), which are designed in particular as elongated holes, are introduced into the counter-plate (14, 18), wherein the guide recesses (30) each interact in a form-fitting manner with a guide means (22). [7] Protective device according to claim 6, characterized by that the guide means (22) is arranged with play in the guide recess (30). [8] Protective device according to claim 6 or 7, characterized by that the guide recesses (30) intersect the edge (32) of the counter-plate (14, 18) and / or are evenly distributed along the outer circumference of the counter-plate (14, 18). [9] Protective device according to one of claims 1 to 8, characterized by that the prestressing element (20) is arranged on a fastening element (34), wherein the fastening element (34) is connected to the counter-plate (14, 18) by at least one fastening means (36). [10] Protective device according to one of claims 1 to 9, characterized by that the prestressing element (20) is designed as a compression or tension spring, wherein the compression or tension spring preferably passes through the counter plate (14, 18) and / or the base plate (12, 16). [11] Protective device according to one of claims 1 to 10, characterized by that a transmission device is included which transmits data from the sensor (24). [12] Protective device according to one of claims 1 to 11, characterized by in that a single sensor (24) is included for detecting the spacing of the counter-plate (14, 18) and the base plate (12, 16), by means of which both a spacing of the first counter-plate (14) from the first base plate (12) and a spacing of the second counter-plate (18) from the second base plate (16) can be detected. [13] Handling system (100) with a protective device (10) according to one of the preceding claims and a handling device (104) and a handling module (102), wherein the handling module (102) is arranged on a first counter-plate (14) of the protective device (10) and the handling device (104) is arranged on a second counter-plate (18) of the protective device (10).

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