Apparatus and method for automatically removing a grinding disc

Abstract

To provide an exchange station which enables automatic exchange of a grinding disk in a relatively simple manner. [Solution] An apparatus is disclosed that includes a retaining plate having a surface for retaining an abrasive disc, a movable clamping element raised to a first position relative to the retaining plate, an actuator coupled to the clamping element and configured to move the clamping element to a second position in which the clamping element is pressed against the retaining plate so that the abrasive disc is clamped between the retaining plate and the clamping element, and a trigger element positioned relative to the retaining plate to be activated when the abrasive disc is placed and pressed against the surface of the retaining plate, wherein the trigger element and the actuator are coupled such that when the trigger element is activated, the actuator moves the clamping element from the first position to the second position.

Description

[Technical Field]

[0001] The present invention relates to an exchange station that enables automatic exchange of abrasive materials (grinding discs, etc.) in a robot-assisted grinding machine. [Background technology]

[0002] Grinding machines are widely used in industry and crafts. Eccentric grinding machines superimpose a rotary motion around a rotation axis on an oscillatory motion. They are often used for finishing surfaces with high demands on surface quality, such as spot repair of surface defects on painted surfaces. To meet these demands, it is necessary to avoid unevenness during the grinding process as much as possible. In practice, these tasks are usually performed by experienced, skilled workers, especially in small-lot production.

[0003] In robot-assisted grinding systems, a grinding tool (e.g., an orbital grinding machine) is guided by a manipulator, such as an industrial robot. The grinding tool can be coupled to the manipulator's TCP (Tool Center Point) in various ways, allowing the manipulator to virtually freely adjust the tool's position and orientation. Industrial robots typically perform position control and can accurately move the TCP along the desired trajectory. To achieve good results in robot-assisted grinding, many applications require control of the grinding force, but conventional industrial robots often have difficulty achieving sufficient precision. Because industrial robots have large and heavy arms, the inertia is large, making it difficult for their control systems (closed-loop control systems) to respond quickly to fluctuations in the grinding force. To solve this problem, a linear actuator, smaller than that of an industrial robot, can be placed between the manipulator's TCP and the grinding tool, coupling the manipulator's TCP and the grinding tool. The linear actuator controls only the grinding force (contact force between the tool and workpiece), while the manipulator moves the grinding tool and linear actuator along a predetermined trajectory with position control. Summary of the Invention [Problem to be solved by the invention]

[0004] Grinding machines, such as eccentric grinding machines, work with thin, flexible, and detachable abrasive discs that are attached to a support plate. These abrasive discs are often so-called daisy discs. The abrasive discs can, for example, have a paper (or other fiber-bonded material) coated with abrasive grains and can be attached to the support disc by means of an adhesive layer or hook-and-loop fasteners (Velcro™ Fasteners). Even in robot-assisted grinding machines, worn abrasive discs are often replaced manually. While there are several robot-assisted exchange station concepts for changing abrasive discs, the known solutions are relatively complex, costly, and therefore expensive.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a changing station in a robot-assisted grinding machine which allows for automatic changing of grinding discs in a relatively simple manner. [Means for solving the problem]

[0006] The above problem is solved by an apparatus according to claim 1 and a method according to claim 9. Different embodiments and further developments are the subject of the dependent claims.

[0007] An apparatus for automatically removing an abrasive disc from a grinding machine mounted on a manipulator is described. The apparatus includes a retaining plate having a surface for retaining an abrasive disc, a movable clamping element raised to a first position relative to the retaining plate, an actuator coupled to the clamping element and configured to move the clamping element to a second position where the clamping element is pressed against the retaining plate so that the abrasive disc is clamped between the retaining plate and the clamping element, and a trigger member positioned relative to the retaining plate to be actuated when the abrasive disc is placed against and pressed against the surface of the retaining plate. The trigger element and the actuator are coupled (directly or indirectly, electrically or mechanically) such that, when actuated, the actuator moves the clamping element from the first position to the second position.

[0008] Further, a method for automatically removing an abrasive disc from a grinding machine mounted on a manipulator is described, the method comprising the steps of placing an abrasive disc attached to the grinding machine onto a retaining plate of an removing device by a manipulator, whereby placing the abrasive disc on the retaining plate activates a trigger element of the removing device, clamping the abrasive disc between the retaining plate and a movable clamping element that is urged toward the retaining plate in response to activation of the trigger element, and lifting the grinding machine by the manipulator, thereby peeling the clamped abrasive disc from a support plate of the grinding machine. [Effects of the Invention]

[0009] In a robot-assisted grinding machine, a change station can be provided which allows the grinding discs to be changed automatically in a relatively simple manner. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a diagram illustrating an example of a robot-assisted grinding device.

[0011] [Figure 2] FIG. 10 shows a robot-mounted grinding machine when the grinding disc is automatically removed by the removal device.

[0012] [Figure 3] FIG. 1 shows an example of an unloading device suitable for automatically unloading a grinding disc from a robot-mounted grinding machine.

[0013] [Figure 4] 4 is a cross-sectional view showing the interior of the removal device shown in FIG. 3 in more detail.

[0014] [Figure 5] 5 is a view showing the state in which the grinding disc is clamped in the embodiment of FIG. 4. FIG.

[0015] [Figure 6] FIG. 6 is a top view corresponding to FIG. 5.

[0016] [Figure 7] 1 is a flow chart illustrating an example method for automatically removing an abrasive disc from a robotically assisted grinding machine. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will now be described in more detail with reference to the embodiments shown in the drawings. The illustrations are not necessarily to scale, and the invention is not limited to the illustrated aspects. Rather, emphasis is placed on illustrating the principles underlying the invention.

[0018] Before describing various embodiments of the present invention in detail, a general example of a robot-assisted grinding apparatus will be described. This apparatus includes a manipulator 1, such as an industrial robot, and a grinding machine 10 (e.g., an orbital grinding machine) equipped with a rotating grinding tool. The grinding tool is coupled to the so-called Tool-Center-Point (TCP) of the manipulator 1 via a linear actuator 20. In the case of an industrial robot with six degrees of freedom, the manipulator may consist of four segments 2a, 2b, 2c, and 2d connected by joints 3a, 3b, and 3c, respectively. The first segment is usually (but not necessarily) rigidly connected to a base 41. Joint 3c is connected to the segments 2a, 2b, 2c, and 2d. 2c Joint 3c may be biaxial, allowing segment 2c to rotate about a horizontal axis (elevation) and a vertical axis (azimuth). Joint 3b connects segment 2b to segment 2c, allowing pivoting of segment 2b relative to the position of segment 2c. Joint 3a connects segment 2a to segment 2b. Joint 3a may be biaxial, allowing pivoting in two directions (like joint 3c). The TCP has a fixed position relative to segment 2a, which typically includes a revolute joint (not shown) that allows pivoting about the longitudinal axis of segment 2a (shown by a dashed line in FIG. 1 and corresponding to the rotation axis of the grinding tool). Each axis of the joint is assigned an actuator (e.g., an electric motor) that can cause rotation about the respective joint axis. The joint actuators are controlled by the robot controller 4 according to the robot program.

[0019] The manipulator 1 is usually position-controlled, i.e. the robot controller determines the pose (position and orientation) of the TCP and can move it along a predefined trajectory. If the actuators 20 are at their end stops, the pose of the TCP also defines the pose of the grinding machine. As mentioned at the beginning, the actuators 20 control the position of the tool and the workpiece during the grinding process. W The contact force (machining force) between the manipulator 1 and the workpiece is set to the desired value. Direct force control by the manipulator 1 is usually too imprecise for grinding applications, since the high mass inertia of the segments 2a-2c of the manipulator 1 allows for fast correction of force peaks (e.g., by moving the grinding tool towards the workpiece). W This is because it is practically impossible with conventional manipulators to move the TCP (when placed on top of the robot). For this reason, the robot control unit controls the attitude of the TCP of the manipulator, and the actuator 20 is solely responsible for controlling the force.

[0020] As previously mentioned, during the grinding process, the tool (grinding machine 10) and the workpiece W The contact force F between K grinding tool and workpiece W The contact force between the workpiece and the linear actuator 20 can be set by the (linear) actuator 20 and the force control (which can be realized in the control unit 4, for example) so that it corresponds to a predetermined value. The contact force in this case is a reaction to the actuator force with which the linear actuator 20 presses the surface of the workpiece. W If there is no contact between the workpiece and the tool, the actuator 20 WThe manipulator 1 moves to the end stop upon loss of contact force. The position control of the manipulator 1 (which can also be realized by the control unit 4) can be performed completely independently of the force control of the actuator 20. The actuator 20 is not used for positioning the grinding machine 10, but only for setting and maintaining the desired contact force during the grinding process and for detecting contact between the tool and the workpiece. The actuator may be a pneumatic actuator, for example a double-acting pneumatic cylinder. However, it is also possible to use other pneumatic actuators, such as bellows cylinders or air muscles. Alternatively, an electric direct drive (gearless) is also conceivable.

[0021] In the case of pneumatic actuators, force control can be realized in a manner known per se with the help of control valves, controllers (implemented in the control unit), and compressed air accumulators. However, the specific implementation is not important for further explanation and will not be described in detail. Instead of the actuator 20, passive smooth elements such as springs can be used, depending on the application. It is also possible to omit the actuator 20 if the force control is provided with sufficient quality by the manipulator itself.

[0022] The grinding machine 10 has an abrasive disc 11 attached to a support plate (backing plate) 12. The surface of the support plate 12, the back surface of the abrasive disc 11, or both, are configured to allow the abrasive disc 11 to easily contact and adhere to the support plate 12. For example, the abrasive disc 11 is attached to the support plate using hook-and-loop fasteners (Velcro™ Fasteners). A common alternative to hook-and-loop fasteners is to apply an adhesive coating to the back surface of the abrasive disc 11, which is then attached to the corresponding surface of the support plate 12. FIG. 2 shows an example of a manipulator-mountable grinding machine 10 positioned relative to an abrasive disc removal device 30 so that the abrasive disc 11 is pressed (e.g., with an adjustable force) against the surface of a retaining plate 35 of the abrasive disc removal device 30. One embodiment of the abrasive disc removal device 30 will now be described in more detail with reference to FIGS. 3-6.

[0023] FIG. 3 is a perspective view of the abrasive disc removal device 30 of FIG. 2 , and FIG. 4 is a corresponding cross-sectional view showing components disposed inside the housing 31 of the removal device 30. It should be noted that the housing 31 of the removal device 30 does not necessarily need to be enclosed. Rather, it is understood that the housing is any mechanical structure to which other components of the removal device 30 can be directly or indirectly, movably or immovably attached. The housing may also have a frame to which one or more covers are attached (in the case of an at least partially enclosed housing). In the example shown, the housing 31 is made up of multiple parts connected by screws. Of course, other connection methods, such as rivets or snap-in connections, are also possible. Depending on the application, the shape of the housing may also differ from the embodiment described here. In the example shown, the housing has a base plate 310 having holes 311. The base plate 310 (and therefore the entire device 30) can be attached to the floor or other support by screws (not shown) inserted through the holes 311.

[0024] As can be seen from Figure 3, the holding plate 35, against which the robot presses the grinding disc 11 attached to the grinding machine 10 during the removal process, has an opening through which the end of the trigger element 33 is guided. The end of the trigger element 33 protrudes from the opening of the holding plate 35, and when the grinding disc 11 is pressed against the holding plate 35 and placed flat against the holding plate 35 during the removal process, the protruding end of the trigger element 33 is forced into the opening (see Figure 4, contact pressure F A ). The opening can also be configured as a slot. The end of the trigger element 33 does not necessarily have to pass through the opening in the holding plate 35. Alternatively, the trigger element 33 can be arranged next to the holding plate. What is important is that the trigger element 33 is arranged so that it is activated when the robot presses the grinding disc 11 against the surface of the holding plate 35.

[0025] When the trigger element 33 is activated (when the grinding disc is pressed against the holding plate 35), it triggers a mechanism that clamps the end of the grinding disc 11 between the holding plate 35 and the clamping plate 34. The robot then again starts the grinding machine. 10 When the removal device 30 is moved away from the support plate 12 of the grinding machine 10, the support plate 12 is lifted from the surface of the holding plate 35, while the abrasive disc 11 is fixed by the clamping plate 34. Lifting the support plate 12 releases the (clamped) abrasive disc 11 from the support plate. An example of the above-mentioned mechanism is described in more detail below with reference to Figures 4 and 5.

[0026] As shown in FIG. 4 , the clamp plate 34 (commonly referred to as a clamping element) is attached to a first end of a rocker lever 342, which is rotatably mounted to a portion of the housing 31 by a joint 341. That is, the rocker lever 342, also referred to as a rocker, can rock around an axis of rotation (defined by the joint 341). The clamp plate 34 (clamping element) may be attached to the rocker lever 341 by, for example, one or more screws 342. In other embodiments, the clamp plate 34 and the rocker lever 341 may be made from a single piece. In the situation shown in FIG. 4 , the rocker lever 342 is positioned so that the clamp plate 34 is lifted from the holding plate 35 (first position). In the situation shown in FIG. 5 , the rocker lever 342 is positioned so that the clamp plate 34 is pressed against the surface of the holding plate 35 (second position), sandwiching a grinding disc between the clamp plate 34 and the surface of the holding plate 35 (if correctly positioned on the holding plate 35).

[0027] Movement of the rocking lever 342 from the first position (clamp release) to the second position (clamp tightening) is caused by actuation of the trigger element 33. In the example shown in FIGS. 4 and 5, the rocking lever 342 has a stopper 343 that abuts against a corresponding holding surface of the trigger element 33. The trigger element 33, like the rocking lever 342, is rotatably attached to a part of the housing 31 (rotary joint 331), and is pressed by a spring 332 in the normal position where one end of the trigger element 33 protrudes from the surface of the holding plate 35, as shown in FIG. 4. In this normal position, the trigger element 33 acts as a blocking pawl that prevents the rocking lever 342 from moving to the second position (clamp tightening). The stop 343 of the rocking lever 342 abuts against the trigger element 33 (which functions as a blocking pawl), blocking the movement of the rocking lever 342. When the protruding trigger element 33 is pressed against the spring force of the spring 332 towards the surface of the holding plate 35 (when positioning the grinding disc on the holding plate 35), the trigger element 33 swings so that the stop 343 of the swing lever 342 no longer abuts against the trigger element 33 and the swing movement to the second position is no longer prevented.

[0028] In the example shown in FIGS. 4 and 5, when the rocking lever 341 is in the first position (clamp released, rocking lever movement prevented by the blocking claw), the rocking lever 341 is subjected to a biasing force F B When the trigger element 33 is actuated / moved, the blocking pawl (trigger element) releases the rocker lever 341, and the preload force F B This causes the rocker lever to swing suddenly to the second position where the grinding disc is clamped, as shown in Figure 5.

[0029] The preload force F mentioned above Bcan be provided by different preload mechanisms. In the example of Figures 4 and 5, this preload mechanism comprises a pneumatic cylinder 37 disposed between the second end of the rocker lever 341 and a part of the housing 31 (e.g., the mounting bracket 311). The cylinder 37 is connected to the mounting bracket 311 (which can be considered part of the housing) via a joint 374, and the piston rod of a piston 371 disposed in the cylinder is connected to the second end of the rocker lever 341 via a joint 373. When compressed air is applied to the cylinder chamber V1 in Figures 4 and 5, the pneumatic cylinder 37 (with the associated piston 371) generates a pretension force F B When the trigger element 33 is activated, the swing lever 341 is pushed to the second position to clamp the grinding disc 11.

[0030] As mentioned above, after the grinding disc 11 is clamped, the grinding machine 10 4 and 5, the return mechanism is provided by a pneumatic cylinder 37. In this case, the preload mechanism and the return mechanism are one unit. The cylinder 37 may also be a double-acting cylinder. That is, when compressed air is supplied to the cylinder chamber V2 in FIGS. 4 and 5, the pneumatic cylinder 37 generates a preload force F B and a return force F acting in the exact opposite direction. R A return force F R 3, the swing lever 341 swings back to the first position, and the grinding disc is released from the clamp. At this time, the spring 332 pushes the trigger element 33 back to its normal position, and the preload force F B When this occurs, the movement of the swing lever 341 is again prevented (as shown in FIG. 4).

[0031] The compressed air nozzle 32 allows air to be sprayed at high speed onto the grinding disc 11 in the direction of the baffle plate 312, ultimately causing the grinding disc 11 to fall downward, for example, into a container. The compressed air nozzle 32 and the baffle plate are both optional and can actually improve the robustness of the device 30. Since the robot control "knows" that the grinding machine 10 has left the removal device 30, the robot control (see control unit 4 in FIG. 1) can activate not only the compressed air from the nozzle 32 but also the return mechanism (e.g., switching the compressed air from cylinder chamber V1 to cylinder chamber V2). Alternatively, the return mechanism can be activated by tilting the trigger element 33 back to its original position. For this purpose, an electric switch can be coupled to the trigger element 33, and activation of the electric switch can activate the switching of compressed air from cylinder chamber V1 to cylinder chamber V2 and the blowing of compressed air from the nozzle 32. Since various possibilities for realizing the valve control are within the knowledge of an expert, the relevant valves and corresponding valve control are not shown in the figures.

[0032] Some abrasive discs are attached to the support plate 12 (see FIG. 2) by an adhesive layer. In such cases, the abrasive disc may adhere to the clamping plate 34. However, to ensure that the abrasive disc can be removed from the apparatus 30 (e.g., by compressed air flowing from the nozzle 32), one or more pins 38 may be attached (directly or indirectly) to the housing 31. These pins are positioned so that the abrasive disc 11 attached to the clamping plate 34 is pushed away when the clamping plate 34 is returned to its first position. The pins are shown in FIGS. 4 and 5. The top view of FIG. 6, associated with FIG. 5, shows a small recess 38' into which the pin 38 penetrates when the clamping plate 34 moves to its first position (away from the holding plate 35). If the abrasive disc adheres to the clamping plate 34 during this movement, the pin 38 pushes the abrasive disc away from the clamping plate 34 at the end of the movement, releasing it enough to be transported away by compressed air.

[0033] To ensure that the abrasive disc removed from the grinding machine 10 has actually been removed from the removal device 30, the removal device 30 can have a sensor 36. The sensor 36 can be seen in FIGS. 4 to 6 and can be configured, for example, as a reflective light barrier. FIG. 6 also shows a reflector 361 belonging to the light barrier 36. The sensor 36 (e.g., a module consisting of a light-emitting diode and a photodiode) and the reflector 361 are arranged relative to each other so that the light beam emitted by the sensor 36 is interrupted by the abrasive disc. This makes it possible to detect whether the abrasive disc has been removed with compressed air. If not, one or more pulses of compressed air can be supplied by the nozzle 32. If the abrasive disc still adheres to the removal port, a warning signal can be issued. It should be noted that the sensor 36 does not necessarily have to be configured as a light barrier. Since abrasive discs usually have a specific color, an optical color sensor can alternatively be used to detect the presence or absence of an abrasive disc. Alternatively, one or more sensors may be used to monitor whether the abrasive disc falls off the bottom of the apparatus 30 and below the baffle plate 312 .

[0034] The function of clamping the grinding disc 11 between the holding plate 35 and the clamping element 34 (clamping plate) and the actuation of the movement of the clamping element by the trigger element 33 can also be performed in a different way than in the example of Figures 2 to 6. In the following, some important general aspects of the removal device 30 are summarized and further embodiments are described in which certain functions are performed differently than in the example of Figures 2 to 6.

[0035] More generally, the removal device includes a holding plate (e.g., see FIGS. 2 and 6, holding plate 35) having a surface for holding the abrasive disc 11. As shown in FIG. 2, a robot can be used to place the abrasive disc 11 on the surface of the holding plate 35. As can be seen, for example, in FIG. 6, the abrasive disc 11 does not need to rest completely on the surface of the holding plate 35. It is sufficient if only a portion of the abrasive disc rests on the holding plate 35. The removal device also includes a movable clamping element (e.g., see FIGS. 4 and 5, clamping element 34), which is raised to a first position relative to the holding plate. That is, in the first position, the clamping element is not in contact with the holding plate. The removal device also includes an actuator coupled to the clamping element and configured to move the clamping element to a second position (see FIG. 5) in which the clamping element is pressed against the holding plate and the abrasive disc is clamped between the holding plate and the clamping element. The trigger element is coupled to the actuator (directly or indirectly depending on whether the actuator is mechanical or electrical) such that, when the trigger element is actuated, the actuator moves the clamping element from the first position to the second position. The trigger element protrudes from the surface of the retaining plate such that the trigger element is actuated when a grinding disc (mounted on the grinding machine) is positioned on and moves toward the surface of the retaining plate.

[0036] In the simplest case, the actuator can be a preloaded spring. A pneumatic actuator (pneumatic cylinder-piston unit) can act like a preloaded spring when filled with compressed air. In some embodiments, the clamping element blocks the actuator (see Figure 4, a cylinder preloaded with compressed air) unless the clamping element is activated, and a trigger element abruptly moves the clamping element from a first position (unclamped) to a second position (clamped) when activated (see Figure 5). In this case, the trigger element is a purely mechanical element, essentially functioning as a lever. A return mechanism can be provided to return the clamping element to the first position. When using a double-acting pneumatic cylinder as the actuator, it is possible to generate a return force that returns the clamping element to its initial position accordingly. In the case of a single-acting pneumatic cylinder, a spring can also generate a return force that returns the clamping element to its first position when the single-acting pneumatic cylinder is depressurized. In this example, if the actuator is a simple preloaded spring, the return force can be generated, for example, by a solenoid that can reload the spring. A unit consisting of two (single-acting) pneumatic cylinders is also possible, where one cylinder acts as the (preload) actuator and the other is responsible for the return movement to the first position.

[0037] In other embodiments, the actuator does not need to generate a preload force while its movement is mechanically blocked by a trigger element. Instead, the actuator is actively controlled to move the clamping element from the first position to the second position when a trigger element, which can be an electric switch (e.g., a push button), is activated. This electric switch is positioned to protrude from the holding plate and is "automatically" activated when a grinding disc attached to the grinding machine is placed on the surface of the holding plate. In this case, the actuator can be any actuator (e.g., electric motor, linear motor, pneumatic actuator, solenoid, etc.) configured to move the clamping element from the first position to the second position. Instead of a switch such as a push button, a separate sensor element can be used that can detect when a grinding disc is placed on the holding plate.

[0038] In the embodiment described here, a clamping element is attached to one end of the rocker lever (see FIG. 5). The clamping element and the rocker lever may be integral. In this case, the clamping element and the rocker lever can be made from one piece. The clamping element can be formed as a small plate, which is referred to as a clamping plate as mentioned above. However, the clamping element does not necessarily have to be a small plate; it can also be formed, for example, by several short pins protruding from the rocker lever and used to clamp the grinding disc against the holding plate.

[0039] An example of a method for removing an abrasive disc from a grinding machine mounted on a manipulator is summarized below using the flowchart of FIG. 7. According to the embodiment of FIG. 7, the method comprises the step of placing the abrasive disc mounted on the grinding machine onto a holding plate of the removal device by the manipulator (see FIG. 7, step S1). This situation is also shown in FIG. 4. When the abrasive disc is placed on the holding plate, a trigger element of the removal device is activated (see FIG. 4, trigger element 33 is configured as a blocking claw). The method further comprises the step of clamping the abrasive disc between the holding plate and a movable clamping element that is pressed toward the holding plate in response to activation of the trigger element (FIG. 7, step S2). This situation is also shown in FIG. 5. The manipulator then lifts the grinding machine and pulls the clamped abrasive disc from the support plate of the grinding machine (see FIG. 7, step S3).

[0040] The clamping element is then lifted again to release the clamped abrasive disc. As previously mentioned, the abrasive disc may become stuck to the clamping element, which is undesirable as it makes it impossible to remove the abrasive disc. In such cases, the abrasive disc can be removed using one or more pins (see FIG. 5, pin 38). The pins 38 inhibit the movement of the abrasive disc stuck to the clamping element when the clamping element is lifted, causing the abrasive disc to disengage from the clamping element. The pins may be attached to the housing of the removal device such that when the clamping element is lifted, the pins enter one or more recesses (see FIG. 6, recess 38') in the end of the clamping element. Various other aspects of this method have already been described above in connection with FIGS. 2 to 6, so reference to that description will avoid repetition. [Explanation of symbols]

[0041] 10...Grinding machine 11...Grinding disc 12...Support plate 30...Removal device 32...Compressed air nozzle 33...Trigger element 34...Clamping element 35...Retaining plate 37...Actuator 38...pin 38´…recess 342...Swing lever

Claims

1. a holding plate (35) having a surface for holding the grinding disc (11) in order to remove the grinding disc (11) mounted on the grinding machine (10); a clamping element (34) movable to a first position above the holding plate (35) and to a second position for clamping the grinding disc (11) on the holding plate (35) for lifting the grinding machine (10) by a manipulator (1) and peeling the grinding disc (11) off the grinding machine (10); an actuator (37) coupled to the clamping element (34) and configured to move the clamping element (34) to the second position and press it against the holding plate (35) so that the grinding disc (11) is clamped between the holding plate (35) and the clamping element (34); a trigger element (33) arranged relative to the holding plate (35) so as to be activated when the grinding disc (11) is placed on the surface of the holding plate (35) by the manipulator (1) and pressed by the manipulator (1); and The trigger element (33) and the actuator (37) are coupled together such that, when the trigger element (33) is actuated, the actuator (37) moves the clamp element (34) from the first position to the second position, and the clamp element (34) is maintained at the second position. Device.

2. 2. The apparatus of claim 1, wherein the trigger element (33) is positioned relative to the retaining plate (35) such that the trigger element (33) is mechanically actuated by the grinding disc being pressed against the surface of the retaining plate (35).

3. 3. The device according to claim 1 or claim 2, wherein the trigger element (33) protrudes from the surface of the holding plate (35), and when the grinding disc (11) is placed and pressed against the surface of the holding plate (35), the trigger element (33) is activated.

4. the actuator (37) is a preloaded spring or a preloaded pneumatic or electric actuator (37); 4. The device of claim 1, wherein the trigger element (33) is configured to block movement of the actuator (37) and to release the blockage of movement of the actuator (37) upon actuation of the trigger element (33).

5. 5. Apparatus according to any one of the preceding claims, wherein the clamping element (34) is attached to or forms part of a rocker lever (342).

6. 6. The device of claim 5, wherein the actuator is coupled to the rocker lever (342), the rocker lever (342) connecting the actuator (37) and the clamping element (34).

7. 7. The apparatus of claim 5 or claim 6, wherein the actuator is a double-acting pneumatic cylinder configured to reciprocate the rocking lever (342) so that the clamping element (34) moves to the second position and back to the first position.

8. 8. The device according to claim 1, further comprising one or more pins (38) arranged to release the grinding disc (11) from the clamping element (34) when the clamping element (34) moves to the first position.

9. 9. The apparatus according to claim 1, further comprising a compressed air nozzle (32) for blowing compressed air in the direction of the abrasive disc when the trigger element (33) is actuated to ensure removal of the abrasive disc.

10. a step of placing an abrasive disc (11) attached to a grinding machine (10) on a holding plate (35) of a removal device (30) by a manipulator (1), and a trigger element (33) of the removal device (30) is activated upon detecting that the abrasive disc (11) has been placed on the holding plate (35); clamping the grinding disc (11) between the retaining plate (35) and a clamping element (34) that is pressed by an actuator (37) toward the retaining plate (35) in response to actuation of the trigger element to move from a first position above the retaining plate (35) to a second position where the clamping element clamps the grinding disc (11) on the retaining plate (35) and is maintained at the second position; Lifting the grinding machine (10) by the manipulator (1), thereby removing the clamped grinding disc from the support plate (12) of the grinding machine; A method having the following.

11. 11. The method according to claim 10, wherein the trigger element (33) of the removal device (30) is mechanically actuated by placing the grinding disc (11) on the holding plate (35).

12. Lifting the clamping element (34) to release the clamped grinding disc (11); If the abrasive disc (11) is attached to the clamping element (34), peeling the abrasive disc (11) off by one or more pins (38) that block the movement of the abrasive disc (11) when the clamping element (34) rises so that the abrasive disc (11) is peeled off from the clamping element; 12. The method of claim 10 or claim 11, further comprising:

13. 13. The method of claim 12, wherein the pin (38) is mounted to the housing of the removal device (30) such that the pin (38) enters one or more recesses (38') in the end of the clamping element (34) when the clamping element (34) is lifted.

14. 14. The method according to any one of claims 10 to 13, wherein upon actuation of the trigger element (33), the preloaded movement of the actuator (37) is released, whereby the clamping element (34) moves from the actuator (37) towards the retaining plate (35) and clamps the grinding disc (11) between the retaining plate (35) and the clamping element (34).

15. 15. The method according to any one of claims 10 to 14, wherein one end of the trigger element (33) protrudes from the surface of the holding plate (35), and the trigger element (33) is activated when the grinding disc (11) is placed on the surface of the holding plate (35) and pressed.

16. 16. The method according to claim 15, wherein the trigger element (33) is a blocking pawl or a push button.

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