Method and system for grasping and moving an object

Abstract

A method for gripping and moving a processed piece (51) obtained by cutting and / or drilling at least one sheet metal (50) and placed on a work surface (110) by means of a gripping and moving system (100) provided with a detection device (1) comprises: Step 1: Positioning the gripping means (101) of the gripping and moving system (100) on the small piece (51) to be lifted; a step (step 2) of positioning the sensor device (4) of the detection device (1) by moving the sensor device (4) along a first direction (X) to a first position (A1, B1), wherein at the first position (A1, B1), the sensor device (4) is aligned with a protrusion on the periphery of the small piece (51) along a second direction (Y), and the second direction (Y) is perpendicular to the first direction (X); a step (step 3) of gripping the small piece (51) with the gripping means (101) and lifting it to a certain height relative to the work surface (110); a step (step 4) of activating the sensor device (4) and moving the sensor device (4) to a second position (A2, B2) to scan a predetermined portion (A, B) of the work surface (110) below the lifted small piece (51) to detect a gap or a remaining connection between the lifted small piece (51) and the thin metal sheet (50); Includes.

Description

[Technical Field]

[0001] The present invention relates to a gripping and transferring method and system for interfacing with an automatic machine for cutting and / or perforating metal sheets, for lifting, removing and transferring finished pieces from the sheet metal after cutting and / or perforating. More precisely, the present invention relates to a gripping and transferring method that makes it possible to verify that the finished pieces have been correctly removed from the sheet metal after cutting and / or perforating. Furthermore, the present invention relates to a system for gripping and transferring finished cut pieces, which is provided with a detection device and can be interfacing with an automatic machine for cutting and / or perforating sheet metal. [Background technology]

[0002] Systems for gripping and transferring processed pieces / objects are known and are used in machines for cutting and / or drilling sheet metal. The machines include a detection device using a sensor capable of scanning the upper surface of the machine's work surface, on which the sheet metal to be cut and / or drilled and the resulting pieces / objects are placed. More precisely, during the final step of each cutting and / or drilling process, during the removal process from the machine's work surface, the detection device verifies that the lifted piece, lifted by a suitable gripping means of the gripping and transferring system, is completely separated from the remaining part (skeleton) of the sheet metal. This prevents the gripping means from lifting and / or dragging the entire sheet metal, along with the pieces, as a result of incomplete cutting and / or drilling.

[0003] In particular, the sensor of the detection device, which is typically an optical sensor, scans the entire work surface during the removal process to detect the presence or absence of an obstacle between the small piece picked up by the gripping means and the sheet metal, i.e., the absence of a gap or space of a certain height (typically 20 mm), which indicates that the small piece has not been effectively and completely removed and separated from the sheet metal.

[0004] It is known to use detection devices including a rotating head that emits a laser beam that can scan the work surface relatively quickly. However, these devices must be positioned at a certain distance from the work surface so as not to interfere with the lifting and movement of the chips. Therefore, the resolution guaranteed by the device decreases with increasing distance and is generally low, sometimes even lower than the thickness of the chips and sheet metal. As a result, it is not possible to guarantee correct identification of the chip removal.

[0005] It is also known to use photosensitive safety barriers employing linearly arranged LEDs adapted to send pulsed infrared light to multiple receivers to create a light screen capable of intercepting improperly removed particles, however these systems also have a low scanning resolution (10-15 mm).

[0006] Furthermore, detection devices have been used that include a laser sensor capable of emitting a laser beam and receiving the reflected light. The sensor can move parallel to one edge of the work surface, continuously scanning the entire work surface. To reduce the time required for scanning, these devices include multiple laser sensors that are spaced apart from each other and movable together. These scanning systems guarantee high resolution (2.5-3 mm), but still require a certain amount of time (2-4 seconds) to scan the entire work surface.

[0007] Furthermore, detection devices that utilize vision systems to detect the outline of the chip and the sheet metal, and in particular to determine the gap or distance between the chip and the sheet metal following lifting and lifting, are known and in use, however, vision systems are quite expensive and difficult to install and adjust.

[0008] The object of the present invention is to improve known methods and systems for gripping and transferring, which can be interfaced with automatic cutting and / or drilling machines and are adapted to safely and reliably lift and transfer finished pieces from the sheet metal after cutting and / or drilling.

[0009] Another object of the present invention is to provide a method and system for gripping and moving that allows for quick, precise and accurate verification that the finished piece has been properly removed from the sheet metal after cutting and / or drilling.

[0010] It is a further object to provide a method and system for gripping and moving that allows for high resolution scanning of the work surface of an associated automated sheet metal cutting and / or drilling machine. Summary of the Invention

[0011] In a first aspect of the present invention, there is provided a method for gripping and moving as set forth in claim 1.

[0012] In a second aspect of the present invention, there is provided a gripping and moving system as set forth in claim 6. [Brief explanation of the drawings]

[0013] The invention can be better understood and practiced with reference to the accompanying drawings, which show exemplary, non-limiting embodiments, in which: [Figure 1] 1 is a perspective view of a gripping and moving system according to the present invention with an associated work surface; FIG. [Figure 2] FIG. 2 is a perspective view of a detection device of the gripping and moving system of FIG. 1. [Figure 3] 3 is a perspective view of the detection device of FIG. 2 with the covering case removed. [Figure 4] 2 is a schematic plan view of the gripping and transfer system and work surface of FIG. 1 in a first step of lifting each piece. [Figure 5] 2 is a schematic plan view of the gripping and transfer system and work surface of FIG. 1 in a second step of lifting each piece. DETAILED DESCRIPTION OF THE INVENTION

[0014] A gripping and moving system 100 of the present invention provided with a detection device 1 will be described with reference to FIGS.

[0015] The gripping and moving system 100 can be coupled to a work surface 110 adapted to support at least one metal sheet 50 to be machined and / or a machined piece 51. The work surface 110 is, for example, the work surface of an automated machine for cutting and / or drilling the metal sheet 50 to produce the finished machined piece 51.

[0016] The detection device 1 (hereinafter also referred to as device 1) is fixed to a side portion 111 of the work surface 110.

[0017] The apparatus 1 comprises a support element 2. The support element 2 extends in particular along a first direction X parallel to the side 111 and is provided with linear guide means 3. The linear guide means 3 is for supporting a sensor device 4 so that it can slide along the first direction X. The sensor device 4 is configured to detect gaps or residual connections between each small piece 51 and the sheet metal 50. It may in fact happen that, upon finishing machining (cutting and / or drilling) the sheet metal 50, the obtained machined small pieces 51 are not completely separated from the remaining part (skeleton) of the sheet metal 50 but remain connected to the remaining part at one or more points. Furthermore, when moving the work surface, it may happen that some of the cut small pieces become separated and remain in an incorrect position.

[0018] The sensor device 4 comprises, for example, a laser scanner sensor, in particular an amplified optical sensor, in particular a polarized retro-reflective amplified optical sensor with a reflector, in particular a reflector or a corresponding reflective element of known type (not shown), arranged to reflect the laser beam emitted by the sensor and attached to the opposite side of the work surface 110 from the sensor itself.

[0019] The apparatus 1 is fixed to the side 111 of the work surface 110, with the sensor device 4 facing the work surface 110 to detect the presence of any remaining connections between each small piece 51 and the sheet metal 50.

[0020] The apparatus 1 further includes a drive means 5. The drive means 5 is coupled to the support element 2 and configured to position and move the sensor device 4 in a controlled manner along a first direction X. In particular, the drive means 5 is configured to position and move the sensor device 4 to scan predetermined portions A, B of the work surface 110. In particular, portions A, B extend along a second direction Y that is substantially perpendicular to the first direction X. The apparatus 1 includes a carriage 6. The carriage 6 is coupled to the guide means 3, is movable along the guide means 3, and supports the sensor device 4. The carriage 6 is driven along the guide means 3 by the drive means 5.

[0021] The guide means 3 comprises, for example, a linear guide or rail of known kind, along which the carriage 6 is connected and can slide.

[0022] The drive means 5 comprises, for example, a rotary electric motor 8, in particular a position- and / or speed-controllable brushless electric motor. More precisely, the rotary electric motor 8 is a step-by-step motor, i.e. a synchronous DC motor, which allows precise control of the positioning of the sensor 4. The drive means 5 may alternatively comprise other types of electric motor, such as, for example, an inverter-controlled asynchronous motor.

[0023] The drive means 5 further comprises delivery means 9, which are driven by the rotary motor 8, connected to the sensor device 4 and adapted to move the sensor device 4 linearly along the guide means 3. In particular, the delivery means 9 comprise at least one endless moving belt 11, in particular of the toothed type, wound around pulley means 12, 13. The pulley means 12, 13 are rotatably fixed to the support element 2, and the carriage 6 is connected to the moving belt 11.

[0024] The pulley means 12, 13 comprise a plurality of return pulleys 12 and drive pulleys 13 which are driven to rotate by the rotary electric motor 8. More precisely, the pulley means 12, 13 are located at the ends of the support element 2 and are mechanically interconnected by a moving belt 11.

[0025] The support element 2 comprises a housing 10 adapted to enclose at least the guide means 3 and the drive means 5 and provided with a longitudinal opening 7. The opening 7 extends at and along the guide means 3 and allows the sensor device 4 to be scanned from outside the support element 2.

[0026] The apparatus 1 further comprises a connecting bracket 15 for fixing both ends of the support element 2 to the work surface 110. Furthermore, the connecting bracket 15 allows for fine adjustment of the laser beam emitted by the sensor device 4 relative to the work surface and, if present, to a retro-reflective surface.

[0027] The gripping and moving system 100 includes a gripping means 101 configured to grip a machined piece 51 obtained by cutting and / or drilling a sheet metal 50 and lift it from a work surface 110.

[0028] The gripping and moving system 100 includes a control unit 60. The control unit 60 is arranged to control the gripping means 101 and the detection device 1, and to control the drive means 5 of the detection device 1, thereby positioning and moving the sensor device 4 along a first direction X to scan a predetermined portion A, B of the work surface 110. In the predetermined portion A, B, there is at least one small piece 51 to be lifted and raised by the gripping means 101.

[0029] More precisely, the control unit 60 coordinates the movements of the gripping means 101 with the movements of the sensor device 4 to reduce waiting times during which the machine is not in operation.

[0030] In particular, the control unit 60 is configured to control the gripping means 101 and the detection device to execute the following steps of the gripping and moving method of the present invention.

[0031] The method according to the invention for gripping and transferring a machined piece 51, obtained by cutting and / or drilling at least one metal sheet 50 and placed on a work surface 110, by means of a gripping and transferring system 100 provided with a detection device 1, comprises: - positioning the gripping means 101 of the gripping and moving system 100 on at least one piece 51 to be lifted from the work surface 110 (step 1); - positioning the sensor device 4 of the detection device 1 by moving the sensor device 4 to a first position A1, B1 along a first direction X, in which the sensor device 4 is substantially aligned with a peripheral protrusion of the small piece 51 along a second direction Y, the second direction Y being substantially perpendicular to the first direction X (step 2); - a step (step 3) of gripping the small piece 51 by the gripping means 101 and lifting it to a certain height relative to the work surface 110; - a step (step 4) of activating the sensor device 4 and moving the sensor device 4 to a second position A2, B2 to scan predetermined portions A, B of the work surface 110 below the lifted small piece 51 in order to detect a gap or a remaining connection between the small piece 51 and the thin plate 50; Includes.

[0032] The method comprises: Step 5: Stopping the lifting of the small piece 51 when the sensor device 4 detects a remaining connection between the small piece 51 and the thin metal sheet 50; or alternatively, If the sensor device 4 does not detect any remaining connection between the lifted small piece 51 and the thin plate 50, the small piece 51 is further lifted and moved out of the work surface 110 (step 6). Further includes:

[0033] In particular, referring to Figures 4 and 5, the predetermined portions A, B of the work surface 110 scanned by the sensor device 4 extend along the second direction Y and have a width along the first direction X equal to the distance between the first positions A1, B1 and the second positions A2, B2, and substantially greater than or equal to the maximum dimension of the small pieces 51 along the first direction X.

[0034] The method further includes repeating steps 1 through 5, or steps 1 through 4 and 6, for each piece 51 to be lifted from the work surface 110.

[0035] The method of the present invention comprises: Positioning the gripping means 101 on a predetermined number of machined pieces 51 to be lifted from the work surface 110 (Step 1); a step of gripping and lifting the predetermined plurality of small pieces (51), in which the predetermined portions A and B of the work surface 110 scanned by the sensor device 4 are below the predetermined plurality of small pieces 51 lifted by the gripping means 101; Further includes:

[0036] In this case, the sensor device 4 detects any remaining connection points that may exist between each of the pulled-up small pieces 51 and the thin metal plate 50 .

[0037] Operation of the gripping and transferring system 100 of the present invention to perform the above-described method for gripping and transferring includes as a first step the positioning of a sheet metal 50 on a work surface 110. From the sheet metal 50, for example, by a cutting and / or punching process of known types, a plurality of finished pieces 51 are created that are to be lifted and removed by the gripping means 101.

[0038] To completely remove them, the detection device 1 must ensure that each small piece 51 is actually detached from the framework of the sheet metal 50, so that the gripping means 101 does not lift the sheet metal 50 together with the small piece.

[0039] For this purpose, the control unit 60 of the detection apparatus 1 controls and coordinates the movements of the gripping means 101 and the movements of the sensor device 4. More precisely, the control unit 60 controls the gripping means 101 to approach a predetermined small piece 51 to be lifted from the work surface 110, and controls the drive means 5 to move the sensor device 4 along the guiding means 3 to a first position A1. In the first position A1, the sensor device 4 is substantially aligned with a protrusion on the periphery of the small piece 51 along a second direction Y, which is substantially perpendicular to the first direction X (FIG. 4).

[0040] The sensor device 4 may also be moved to the first position A1 before the gripping means 101 is moved.

[0041] The gripping means 101 then grips the small piece 51 and lifts it to a certain predetermined height. The small piece 51 is partially lifted and then placed on the work surface 110 multiple times, typically to avoid leaving any connection points, no matter how small, between the periphery of the small piece 51 and the framework of the sheet metal 50.

[0042] At the end of this procedure, with the small piece 51 raised a certain height (e.g., 40 mm) above the work surface 110, the sensor device 4 is moved by the driving means 5 along the guiding means 3 from the first position A1 to the second position A2, scanning the entire portion A of the work surface 110 below the small piece 51.

[0043] If the sensor device 4 detects a remaining connection between the partially lifted strip 51 and the sheet metal 50, i.e., a lack of clearance between the strip and the plate, it stops lifting the strip and, since the strip is still connected to the sheet metal framework, it is repositioned on the work surface 110. More precisely, the strip 51 is positioned on the work surface 110 and then lifted again for a confirmatory scan.

[0044] On the other hand, if the sensor device 4 does not detect any obstacle or remaining connection between the small piece and the plate, i.e., if it detects a gap between the pulled-up small piece 51 and the thin plate 50, the lifting does not stop, and the small piece 51 is further pulled up and transported outside the work surface 110.

[0045] The electric motor 8 of the drive means 5 is activated in order to move the sensor device 4 along the guide means 3. More precisely, the electric motor 8 moves a moving belt 11 to which the carriage 6 is fixed via a drive pulley 13. The carriage 6 supports the sensor device 4 and can slide along the guide means 3 to position the sensor device 4 in a first position A1 and then in a second position A2 along the first direction X.

[0046] While the small piece 51 is being moved and removed from the work surface 110, the sensor device 4 can be positioned at another first position B1 by the drive means 5. In the first position B1, said sensor device 4 is substantially aligned along the second direction Y with the peripheral projections of the other small piece 51 to be lifted and removed (FIG. 5). It should be noted that the other small piece 51 may be included in the same row as the small piece 51 previously lifted at another position along the second direction Y.

[0047] Once the other piece 51 to be lifted is grasped by the gripping means 101 and lifted, the sensor device 4 can be moved by the driving means 5 to another second position B2 to scan another portion B of the work surface 110 below the partially lifted piece 51.

[0048] This procedure may be repeated successively for all of the pieces 51 to be lifted from the work surface 110.

[0049] In this way, the time required to control the pieces 51 is advantageously significantly reduced, since the time required to verify that each piece 51 has been correctly removed from the sheet metal framework is the time required for the sensor device 4 to scan each of the portions A, B of the work surface 110 corresponding to and below only the piece 51, rather than the entire surface 110 as in known detection systems. This time is of the order of several tens of milliseconds, even for pieces 51 of considerable size, due in part to the operation of the motor 8 of the drive means 5 and the delivery means 9. In particular, the drive means makes it possible to quickly, precisely, and accurately position the sensor device 4, i.e., the carriage 6, along the guide means 3 at the first and second positions A, B identified based on the position along the first direction X of each piece 51 to be lifted.

[0050] Furthermore, the gripping means 10 is configured to simultaneously lift and raise a predetermined number of machined small pieces 51 from the work surface 110. In this case, the predetermined portions A and B of the work surface 110 scanned by the sensor device 4 are portions below the predetermined number of small pieces 51 raised by the gripping means 10, and the sensor device 4 detects any remaining connection points that may exist between each of the plurality of small pieces 51 that have been raised and the thin plate 50.

Claims

1. A method for gripping and moving a processed piece (51) obtained by cutting and / or drilling at least one metal sheet (50) and placed on a work surface (110) by means of a gripping and moving system (100) provided with a detection device (1), comprising: - positioning (step 1) the gripping means (101) of said gripping and moving system (100) on at least one piece (51) to be lifted from said work surface (110), and simultaneously - positioning the sensor device (4) of the detection device (1) by moving the sensor device (4) along a first direction (X) to a first position (A1, B1), in which the sensor device (4) is substantially aligned with the peripheral projection of the small piece (51) along a second direction (Y), the second direction (Y) being substantially perpendicular to the first direction (X) (step 2); - a step (step 3) of gripping said at least one small piece (51) by said gripping means (101) and lifting it to a certain height relative to said working surface (110); - a step (step 4) of activating the sensor device (4) and moving the sensor device (4) to a second position (A2, B2) to scan a predetermined portion (A, B) of the work surface (110) below the lifted small piece (51) in order to detect any gaps or residual connections between the lifted small piece (51) and the sheet metal (50); A method comprising:

2. - a step (step 5) of stopping the lifting of the small piece (51) if the sensor device (4) detects a remaining connection between the lifted small piece (51) and the thin metal sheet (50), or - if the sensor device (4) does not detect any remaining connection between the pulled-up small piece (51) and the thin metal sheet (50), the small piece (51) is further pulled up and moved outside the work surface (110) (step 6). The method of claim 1 further comprising:

3. 3. The method according to claim 1 or 2, wherein the predetermined portion (A, B) of the work surface (110) scanned by the sensor device (4) extends along the second direction (Y) and has a width along the first direction (X) equal to the distance between the first position (A1, B1) and the second position (A2, B2) and substantially greater than or equal to the maximum dimension of the small piece (51) along the first direction (X).

4. 4. The method of claim 1, further comprising repeating steps 1 to 5, or steps 1 to 4 and 6, for each piece to be lifted from the work surface.

5. Step 1: Positioning the gripping means (101) on a plurality of processed pieces (51) to be lifted; a step of gripping and lifting the plurality of processed pieces (51), wherein the predetermined portions (A, B) of the working surface (110) are below the plurality of processed pieces (51) lifted by the gripping means (101); 5. The method of claim 1, comprising:

6. A gripping and moving system (100) connectable to a work surface (110) suitable for supporting a sheet metal (50) to be processed and / or a processed piece (51), - gripping means (101) for gripping and lifting the processed pieces (51) obtained in particular by cutting and / or drilling the sheet metal (50) from the working surface (110); a detection device (1), Including, The detection device (1) a support element (2) extending in particular along a first direction (X) parallel to the sides (111) of said working surface (110) and provided with linear guide means (3); a sensor device (4) adapted to detect the remaining connection between said piece (51) and said sheet metal (50), said sensor device (4) being supported by said guide means (3) so as to be slidable along said first direction (X); - drive means (5) connected to said support element (2) and configured to position and move said sensor device (4) along said first direction (X) in a controlled manner; a control unit (60) configured to control the gripping means (101) and the detection device (1) to carry out each of the steps of the method according to any one of claims 1 to 5; A gripping and moving system (100) comprising:

7. 7. The gripping and moving system (100) of claim 6, wherein the control unit (60) is configured to control the drive means (5) of the detection device (1) to position and move the sensor device (4) along the first direction (X) to scan a predetermined portion (A, B) of the work surface (110), in particular where at least one processed piece (51) is present that has been lifted and partially raised by the gripping means (101).

8. 8. A gripping and moving system (100) as described in claim 6 or 7, wherein the detection device (1) includes a carriage (6), which is connected to the guide means (3), is movable along the guide means (3), and supports the sensor device (4), and the carriage (6) is driven along the guide means (3) by the drive means (5).

9. The drive means (5) comprises a rotary electric motor (8), in particular a brushless electric motor, the position and / or speed of which can be controlled; a delivery means (9) driven by the rotary motor (8), connected to the sensor device (4), and capable of linearly moving the sensor device (4) along the guide means (3); A gripping and moving system (100) according to any one of claims 6 to 8.

10. A gripping and moving system (100) according to claim 9 dependent on claim 8, wherein the delivery means (9) comprises at least one moving belt (11), in particular an endless toothed belt, wound around pulley means (12, 13) rotatably fixed to the support element (2), and the carriage (6) is connected to the moving belt (11).

11. 11. The gripping and moving system (100) according to claim 10, wherein the pulley means (12, 13) comprises a plurality of return pulleys (12) and drive pulleys (13) that are rotationally driven by the rotary electric motor (8).

12. 12. The gripping and moving system (100) according to any one of claims 6 to 11, wherein the support element (2) comprises a covering case (10) suitable for enclosing at least the guide means (3) and the drive means (5) and having a longitudinal opening (7) extending at and along the guide means (3) to enable the sensor device (4) to be scanned from the outside.

13. Gripping and moving system (100) according to any one of claims 6 to 12, comprising connecting brackets (15) for fixing both ends of the support element (2) to the work surface (110).

14. Gripping and moving system (100) according to any one of claims 6 to 13, wherein the sensor device (4) comprises a laser scanner sensor, in particular an amplified optical sensor, in particular a polarized retroreflective amplified optical sensor with a reflector.

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