WO2014162248A1

WO2014162248A1 - Movement system

Info

Publication number: WO2014162248A1
Application number: PCT/IB2014/060257
Authority: WO
Inventors: Massimiliano SALE
Original assignee: Manz Italy S.R.L.
Priority date: 2013-04-05
Filing date: 2014-03-28
Publication date: 2014-10-09
Also published as: ITMO20130088A1

Abstract

A movement system is disclosed that removes an electrode of flat shape from a stack of electrodes and transfers the electrode to a preset position on a production line for producing electric energy accumulating devices, in which the electrode is removed by a suction cup member and the orientation thereof is controlled by two linear photocells and two tip photocells, each photocell being operational in an electrode passage zone.

Description

MOVEMENT SYSTEM

Background of the invention

[0001] The invention relates to a movement system, in particular for transferring flat objects one by one from a removing zone to a release zone, for example by removing the objects from a stack.

[0002] Specifically but not exclusively, the invention can be applied usefully to move flat electrodes within the ambit of a machine for manufacturing electric energy accumulating devices.

[0003] One of the problems of producing electric energy accumulating devices with flat electrodes is to transfer the electrodes (generally of rectangular shape) from a removing zone, where the electrodes are generally stacked on one another in a manner that is not perfectly aligned, to a release zone at the assembly line of the accumulating device, such as to arrange the electrodes with the desired orientation with great precision.

[0004] Controlling the orientation of the electrodes by means of an artificial vision system that is provided with one or more cameras and is used to guide the movement device (generally of the suction cup type) that transfers the electrodes is known.

[0005] The prior art nevertheless has various limits and drawbacks.

[0006] Firstly, known systems require considerable space for a complete view of the electrode in order to detect the orientation thereof. Secondly, it is desirable to improve the accuracy of the camera/s. Further, the artificial vision system requires appropriate lighting and can in certain cases be subject to error because of the colour or degree of reflection of the electrode.

[0007] EP 2421034 discloses a system as in the preamble of claim 1.

Summary of the invention

[0008] One object of the invention is to improve the prior art, in particular by overcoming one or more of the drawbacks disclosed above.

[0009] One advantage is devising a movement system with an accurate and effective control of the positioning of the moved object.

[0010] One advantage is to provide a system for moving flat objects in a precise manner, in particular flat objects with a perimeter of substantially polygonal shape (for example with three, four or more sides, with optionally chamfered or rounded tops), or a curved shape, or a mixed shape with curved and straight sides.

[0011] One advantage is to make a movement system available that is able to control the positioning of the objects, in particular the correct alignment thereof along a work line (for example an assembly line that uses the objects), rapidly and making use of a relatively reduced operating space.

[0012] One advantage is to provide an object movement system that is constructionally simple and cheap.

[0013] One advantage is to enable accurate and reliable control of the positioning of an object regardless of environmental lighting and of optical properties (colour, degree of reflection, etc.) of the object itself.

[0014] Such objects and advantages and others are achieved by the movement system according to one or more of the claims set out below.

[0015] In one embodiment, a movement system comprises at least one gripping member, in particular of the pick and place type, which is able to remove at least one object from a removing zone, for example from a magazine of flat objects that are stacked on one another, in which the positioning of the removed object is controlled by one or two linear photoelectric sensors and one or two tip photoelectric sensors. Each sensor may have two elements (for example an emitter and a receiver) placed in a passage zone of the removed object, on opposite sides thereof.

[0016] In particular, the movement system is able to remove (for example by a suction gripping member) an electrode of flat shape and transfer the electrode to a preset position, in a significantly accurate manner, in a line for manufacturing electric energy accumulating devices.

Brief description of the drawings

[0017] The invention can be better understood and implemented with reference to the attached drawings that illustrate some embodiments thereof by way of non-limiting examples.

[0018] Figure 1 is a top plan view of an embodiment of a movement system according to the invention.

[0019] Figure 2 is a bottom view of figure 1 that is partially sectioned and has some parts removed to show others better.

[0020] Figure 3 is a view, as in figure 2, in one operating configuration in which an object has been removed by the gripping means of the movement system.

[0021] Figure 4 is the view of figure 3 in which the spotlights of the photoelectric sensors of the movement system have been highlighted. [0022] Figure 5 is a view, as in figure 1, during control of the orientation of the object removed by the gripping means of the movement system.

[0023] Figure 6 is a top plan view, similar to figure 5, of a second embodiment of a movement system according to the invention.

Detailed description

[0024] With reference to the aforesaid figure, with 1 a movement system for objects 2 has been indicated overall, in particular for moving flat objects. The objects 2 may be, as in the specific example disclosed here, flat objects. The flat objects may have, for example, a polygonal shape (with three, four, five or more sides) with optionally chamfered, sheared or rounded vertexes. More in particular, the objects 2 to be moved may comprise, as in this case, flat electrodes used for manufacturing electric energy accumulating devices.

[0025] The movement system 1 comprises movable gripping means 3 for removing the objects 2 (one by one) from a removing zone and for moving the removed objects 2 along a preset path on the basis of a work programme. The gripping means 3 may be, for example, of the pick and place type. The gripping means 3 may have, in particular, the possibility of moving according to one, two or more translation directions and according to one or more rotation axes. In particular, the gripping means 3 may translate along a horizontal direction (parallel to the Y axis of three Cartesian axes X, Y, Z) and in a vertical direction (parallel to the Z axis). More in particular, the gripping means 3 may translate according to another horizontal direction (parallel to the X axis). The gripping means 3 may rotate around a vertical rotation axis R (parallel to the Z axis).

[0026] The removing zone may comprise, as in this example, a magazine 4 for flat objects 2 stacked on one another. The magazine may comprise a container for the stack of objects 2. In particular the magazine 4 may be suitable for containing a set of flat objects 2, for example of substantially polygonal shape (with the sides optionally linked by curved or rectilinear joints), in the specifically quadrangular (more specifically rectangular) case, as for example flat electrodes used for manufacturing electric energy accumulating devices (batteries, capacitors, etc.). The objects may nevertheless have other shapes. In particular, the contour of the objects may be curved or mixed with curved and straight segments. Further, the removing zone could comprise, in other embodiments, instead of a magazine for storing a plurality of objects, a zone in which the objects are supplied, for example one by one, automatically or manually, in particular during operation of the movement system 1. [0027] The movement system 1 comprises sensor means for detecting (in space) at least one geometrical feature of an object 2 removed by the movable gripping means 3.

[0028] In particular the sensor means may be arranged for detecting the orientation of the object 2 in the space with respect to one or more reference elements and/or the spatial position of the object 2 with respect to an ideal position and/or the shape and dimensions of the object 2 with respect to the nominal shape and dimensions and/or the oscillation of the object 2 with respect to a rotation around a reference axis and/or the tilt of the object 2 in space with respect to a reference plane (or axis) etc.

[0029] In particular, the sensor means is arranged for detecting at least one geometrical feature of a flat electrode to permit correct positioning of the electrode in an electrode arranging zone in the ambit of an automated assembly line of an electric energy accumulating device.

[0030] The sensor means may be operationally associated with (programmable) electronic control means that controls the gripping means 3 in response to signals emitted by the sensor means, in order to position the object in the preset position, in particular with the desired orientation and/or tilt and/or alignment along the assembly line of the electric energy accumulating device.

[0031] Such sensor means may comprise first photoelectric sensor means arranged for operating on at least one first zone intended for the passage of the object 2 moved by the gripping means 3.

[0032] The first photoelectric sensor means may comprise, as in the specific case disclosed here, two high-precision (5 micron) analogue linear photocells 5, for example two laser photocells.

[0033] Such sensor means may further comprise second photoelectric sensor means arranged for operating on at least one second zone intended for the passage of the object moved by the gripping means.

[0034] The second photoelectric sensor means may comprise, as in the specific case disclosed here, two digital tip photocells 6, with high-speed detection (response time: 20 microseconds), for example two optic fibre photocells.

[0035] In particular, the first photoelectric sensor means may be, as in this example (two linear photocells 5), of linear type with at least one linear spotlight L. The first photoelectric sensor means may comprise, more in particular, at least two linear spotlights L that may be arranged, as in the case in point, on opposite sides of the (preset) passage path of the object 2 moved by the gripping means 3.

[0036] Each linear spotlight L may be, as in this specific example, arranged transversely to a movement direction F according to which the object moves along the passage path during detection by the first photoelectric sensor means. In the specific case the movement direction F is a direction that is parallel to the lying plane of the flat objects 2. In particular, the movement direction F is horizontal. More in particular, the movement direction F corresponds to the direction of the Y axis.

[0037] In particular the second photoelectric sensor means may be, as in this example (two digital tip photocells 6), of tip type with at least one tip spotlight P. The second photoelectric sensor means may comprise, more in particular, at least two tip spotlights P arranged at a mutual distance along the passage path of the object 2. The aforesaid mutual distance may have, as in the case in point, at least one component that is transverse to the movement direction F according to which the object moves along the passage path during detection by the second photoelectric sensor means.

[0038] The first photoelectric sensor means may comprise one or more, in particular two as in this example (two linear photocells 5), pairs of elements interacting with one another and arranged on opposite sides of the free space that permits the passage of the flat object 2, such that the object, by traversing the free space, passes through the two elements of each pair of elements. As in the specific case (two barrier linear photocells 5) the first photoelectric sensor means may be sensor means of the barrier type, so each pair of elements will comprise an emitter and a receiver.

[0039] The second photoelectric sensor means may comprise one or more, in particular two as in this example (two tip photocells 6), pairs of elements interacting together and arranged on opposite sides of the free space that permits the passage of the flat object 2, so that the object, by traversing the free space, passes between the two elements of each pair of elements. The second photoelectric sensor means may be sensor means of the barrier type, so each pair of elements may comprise an emitter and a receiver.

[0040] In general, in order to make the first and the second photoelectric sensor means disclosed above, it will be possible to use photocells of the barrier type or of another type, for example diffusing photocells (with one element provided with both an emitter and a receiver), reflex photocells (with an emitter-receiver and a reflecting or rear reflecting element), laser photocells, etc.

[0041] The gripping means 3 may comprise, as in this example, sucking gripping means (of the suction cup type). The gripping means 3 may comprise, as in the case in point, a movable gripping plate 7 for gripping and moving at least one object 2 at a time. The driving and moving means (which is not shown) of the gripping means 3 may be of known type. The gripping plate 7 may be a sucked plate (sucked by a suction cup). The gripping plate 7 may have a perimeter edge with at least one recess 8 (recess passing through the thickness of the plate 7). In the specific case, the gripping plate 7 comprises a plurality of recesses 8 (through recesses) distributed over the perimeter of the plate. The sensor means, in particular the second photoelectric sensor means (digital tip photocells 6), may be arranged, for example, to operate on at least one recess 8, when the gripping plate 7 passes that holds the object 2. In the specific case, the flat object 2 (electrode), which is grasped by the gripping plate 7 (by means of a sucking system), remains adhering, by the suction effect, to the lower surface of the plate 7. The gripped object 2, at least a part of the surface of which is substantially covered by the gripping means 3, is uncovered at least at the recess/es 8, so that the sensor means can be more effective if it is placed at at least one recess 8. The gripping of the object 2 by the gripping means 3 is visible in figures 3 and 4, but is even more clearly seen in the top view of figure 5, where the object 2 is retained by the plate 7 and a part of the object is visible from above by the through recesses 8; figure 5 is comparable for reference with figure 1 in which the objects 2 have not been illustrated.

[0042] The gripping means 3 may be movable in such a manner as to maintain a (flat) gripping surface of the flat object 2 (for example the lower flat sucking surface of the gripping plate 7 that grips the electrode) always substantially parallel to itself, in particular always substantially horizontal.

[0043] In use, the gripping means 3 removes an object 2, in particular from the removing zone (for example the electrodes magazine 4). The removed object could be, for example, an object 2 placed at the top of a stack where the objects are stored in a manner that is not perfectly orderly and aligned. In other examples, the removed object could be an object arranged (for example manually) in the removing zone in a position that is not always exactly predefinable with certainty. The gripping means 3 thus moves the object 2 to transfer the object 2 to the use zone in a precise placing zone of the object (for example a flat electrode will be placed on the assembly line of an electric energy accumulating device).

[0044] During the transfer, the object 2 moved by the gripping means 3 is affected by the action of the sensor means (photocells 5 and 6) that detects one or more of the geometrical features thereof. In particular, the photoelectric sensor means can determine the orientation of the object (electrode) with respect to the orientation axis R. If this orientation is not the desired orientation, the control means will rotate the gripping means 3 around the axis R to modify the orientation of the object. The control means may comprise programmable electronic control means (of known type).

[0045] In particular, the sensor means (photocells 5 and 6) may determine the position of the object with a respect to a plan reference system X, Y or spatial reference system X, Y, Z, in particular the coordinate along the X axis and/or the coordinate along the Y axis, so that the control means can control the gripping means 3 in such a manner that the object 2 is released onto the zone of use in the desired location, in particular with the coordinates predefined with respect to the X axis and/or the Y axis. The control means may control the gripping means 3 so that the object 2 is released on the zone of use at the appropriate moment in a manner that is coordinated with the operations that occur in the zone of use (for example according to the operation of the assembly line).

[0046] The control by the movement system can be used to arrange the objects in the desired position (with significant precision) and/or to ascertain the shape and dimensions of the object to be placed (with the possibility of automatically rejecting an object with a shape and/or dimensions that are not appropriate).

[0047] The embodiment illustrated schematically in figure 6 differs from the one previously illustrated in that the gripping means comprises, in this case, suction cup means 9 of dimensions that are such that the gripped object 10 protrudes laterally from the gripping member (suction cup) applied to the object. The suction cup means 9 has, in this case, one gripping member with side dimensions that are less than the side dimensions of the object 10, so the (flat) object 10 will protrude beyond the profile of the gripping member. The gripping means may be, in this case, suitable for use with objects 10 that are relatively more stable geometrically and/or stiffer than the objects 2 disclosed previously (flat electrodes with relatively large dimensions). For the sake of simplicity, the elements similar to those disclosed in figures 1 to 5 have been indicated in figure 6 by the same numbering. In this example, the object 10, which is removed, moved and then positioned in the desired position, may have a different shape from the object 2. The gripping means may have different shapes in the two cases. In particular, the suction cup means 9 may have one gripping member devoid of recesses, as in figure 6. Operation is substantially the same as the operation disclosed previously. In particular, the detecting system that determines at least one geometrical feature of the object 10 removed by the gripping means (suction cup means 9) operates in an analogous manner to what has already been seen with reference to figures 1 to 5.

Claims

1. Movement system (1) comprising:

movable gripping means (3, 9) for removing at least one object (2; 10) from a removing zone (4) and for moving the removed object;

- sensor means for detecting at least one geometrical feature of the object (2; 10) removed by said gripping means (3; 9), said sensor means comprising first photoelectric sensor means (5) arranged for operating on at least a first zone intended for the passage of the object (2; 10) moved by said gripping means (3; 9), and second photoelectric sensor means (6) arranged for operating on at least a second zone intended for the passage of the object (2; 10) moved by said gripping means, said first photoelectric sensor means (5) being of linear type with at least two linear spotlights (L);

characterized in that said second photoelectric sensor means (6) is of the tip type with at least two tip spotlights (P).

2. System according to claim 1, wherein said at least two tip spotlights (P) are arranged for affecting two zones intended for the passage of a frontal edge of the object (2; 10) moved by said gripping means (3; 9).

3. System according to claim 2, wherein said at least two linear spotlights (L) are arranged on opposite sides of a transit route of the object (2; 10) moved by said gripping means (3; 9).

4. System according to claim 3, wherein said at least two linear spotlights (L) are arranged for affecting two zones intended for the passage of two opposed lateral edges of the object (2; 10) moved by said gripping means (3; 9).

5. System according to any preceding claim, wherein said at least two tip spotlights (P) are arranged for affecting two mutually distanced zones of a transit route of the object moved by said gripping means.

6. System according to any preceding claim, wherein said at least two tip spotlights (P) are arranged at a reciprocal distance along a transit route of the object (2; 10) moved by said gripping means (3; 9), said distance having at least one component that is transverse to said movement direction (F).

7. System according to any preceding claim, wherein said gripping means (3) comprises at least one movable gripping element (7) for taking and moving at least one object (2), said gripping element (7) having a perimeter edge with a recess (8), said second photoelectric sensor means (6) being arranged for operating on said recess (8) during the transit of said gripping element (7) with the gripped object (2).

8. System according to any preceding claim, wherein each of said at least two linear spotlights (L) is arranged transversely to a movement direction (F) according to which the object (2; 10) moves along a transit route of the object during detecting.

9. System according to any preceding claim, wherein said removing zone comprises a magazine (4) for flat objects piled up on one another;

10. System according to claim 9, wherein said magazine (4) comprises a magazine of electrodes for electric energy accumulating devices.

11. System according to any preceding claim, comprising a set route travelled by said gripping means (3; 9) for moving the object (2; 10), said route comprising a free space for the transit of a flat object (2; 10) in a movement direction (F) that is substantially parallel to the plane of the object, said first and second photoelectric sensor means (5 and 6) each comprising one or more, in particular two, pairs of elements interacting between themselves and arranged on opposite sides of said free space in such a manner that the flat object, by traversing said free space, passes between the two elements of each pair of elements.

12. System according to any preceding claim, wherein said gripping means (3; 9) is of the pick and place type with the possibility of movement according to two or more translation directions and one or more rotation axes (R).

13. System according to any preceding claim, wherein said removing zone comprises an arranging zone for arranging at least one flat object.

14. Use of a movement system (1) according to any preceding claim for moving flat electrodes for producing electric energy accumulating devices, to detect at least one geometrical feature of the electrodes in the space and to position the electrodes according to said detecting.