FR3081853A1 - DEVICE AND METHOD FOR FOLDING TREATMENT OF CARDBOARD PLATES - Google Patents

Abstract

The present invention relates to a device and a method of treatment by folding of cardboard plates (1) in order to form packaging boxes. The device comprises a transit store (2) of said plates (1); a receiving station (6) for folding; a gripping means (5) movable, on the one hand, according to a forward stroke from said reception station (6) to the store (2) and, on the other hand, according to a return stroke of individual extraction of each plate (1) from said store (2) to the receiving station (6), configured to grip a plate (1) at a gripping area (7) and then release it; characterized in that it comprises means for measuring (9) the position of said plate (1) at its gripping zone (7); means for adjusting said forward stroke of said gripping means (5), as a function of said measured position.

Description

Device and method for processing by folding cardboard plates

The present invention falls within the field of processing by folding cardboard plates in order to form containers, for packaging one or more products therein.

Such containers can be in the form of cardboard boxes or "cartons" for packaging products.

In a known manner, the automated production of cardboard boxes is carried out by folding from cardboard plates previously precut and preformed. To do this, said plates are erected substantially vertically and in a grouped manner within a transit store, supplied from the rear from a plate storage area while at the front, the plates are retained by stops. adapted. The grouped plates generally rest at the level of their lower edge on means ensuring their movement from the rear towards the front of said store. From the front, each plate is seized individually, one by one, so as to supply a reception station, which can in particular be a folding station. Such a folding station can also be arranged downstream of the reception station. Such a folding station, also known as a “forming machine”, comprises means adapted to form from each plate, a cardboard box.

In addition, the entry of each plate is effected by means of suitable means which are movable in a forward stroke from the receiving station to the store, and conversely in a return stroke for extracting a plate from said store. To do this, a movable gripping means is provided with at least one gripping member, in particular by vacuum, such as a suction cup. Each suction cup comes into contact with the front face of the first plate and performs a suction ensuring that said first plate is maintained with a view to its movement along said return stroke from said store to said reception station. Said first plate is then deposited and released at said reception station. The movable gripping means then returns to empty according to its outward travel.

Meanwhile, the next plate takes the place of said first plate. The advancement of the plates within the transit store can in particular be operated in the following two different ways.

Means can be envisaged in order to circulate plates from the rear towards the front of the transit store, such as a lower conveyor in the form of an endless band on which said plates rest. Such means are generally implemented when the trajectory of the plates is horizontal within said store.

In certain cases, the circulation of the plates can take place naturally under the effect of the mass of the superposition of the grouping of plates placed side by side within said store. This generally occurs when the path of the plates from rear to front is inclined in a downward slope.

Within the transit store, the plates are in principle placed against one another and extend substantially vertically. In practice, the cardboard plates are slightly inclined and have a forward tilting angle ranging from ten to thirty degrees (from 10 to 30 °) relative to the vertical. Preferably, this angle ranges from ten to twenty degrees (from 10 to 20 °) and is in particular of the order of ten degrees (10 °).

A recurring problem in the folding of cardboard plates lies in the effect of "curling" of said plates, namely that they deform and bulge, taking a curvature in contact with the ambient air. Indeed, the superposition of said plates and their composition induces a deformation, because its components, namely different assembled cardboard layers, have different hygroscopic characteristics. This deformation is difficult to predict due to the changes in the atmosphere of the cardboard plates, transported and handled from storage places to production places with distinct environmental conditions, generating in particular significant variations in humidity and temperature.

The curling of cardboard plates generates gripping defects by the organs, whose fixed and regulated forward stroke brings at least one suction cup (generally several) to a theoretical position, previously determined in contact with the face of the plate to be grasped, without taking take into account the real deformation of each plate. Indeed, this outward travel is determined by considering that the plates are flat. In short, the contact between at least one suction cup and the plate is not sufficient to apply the seal required to achieve sufficient suction. This results in gripping defects, resulting in poor grip, or even precarious maintenance of said plate at the time of its movement, or even an impossibility of gripping the plate.

To overcome this drawback drawback drawback due to the non-flatness of the cardboard plates, the outward travel of the gripping means can be configured in a fixed manner, beyond the theoretical position, to come to press and push on the front plate, so as to ensure perfect contact with each suction cup and suction. However, this operation generates detrimental mechanical stresses, by compressing the plates towards the rear of the magazine, causing not only faster wear of the components of the gripping means inducing more regular and costly maintenance but also an oversizing of the gripping means.

An alternative solution is to increase the depression, so as to ensure suction and maintenance. In addition to the proportional increase in pneumatic means and their costs, in operation as well as in maintenance, it is necessary to have suction cups with larger bellows, to increase the volume of air drawn in, again causing faster wear and more regular maintenance operations. In addition, over time, the time required to aspirate a larger volume of air affects the rate of extraction of the cardboard plates.

The object of the invention is to overcome the drawbacks of the state of the art by proposing a device for processing by folding cardboard plates, with a view to forming packaging boxes.

Such a processing device is intended to be able to adapt in real time, to each grip as a function of the deformation specific to each plate to be gripped.

To do this, the invention provides for determining the impact of the curvature of each plate, by measuring the position at the level of a defined gripping area, namely the location where the members must come into contact with the face of each plate to grab. From this position, it is then possible to automatically adjust the outward travel of the gripping means, with a view to ensuring perfect positioning of the suction cups and sealing contact with the wall of the plate.

The subject of the invention is a device for processing by folding cardboard plates in order to form packaging boxes. Said processing device comprises a magazine for transit of said plates; a receiving station for folding said plates; at least one mobile gripping means, on the one hand, in a forward stroke from said receiving station to the store and, on the other hand, in a return stroke of individual extraction of each cardboard plate from said store to at the reception station, configured to grab a plate at the level of a gripping area and then release it.

Said treatment device is characterized in that it further comprises means for measuring the position of said plate at least at its gripping zone; means for adjusting said forward stroke of said gripping means, as a function of said measured position.

According to additional, non-limiting characteristics, said measuring means can consist of at least one rangefinder, preferably a laser rangefinder.

Said gripping means may comprise at least one vacuum gripping member in contact with the gripping zone of each plate.

The gripping means can be mounted on a robot, in particular of the multi-axis robot type.

The mobility of the gripping means can be managed by at least one servomotor.

The invention also relates to a method of processing by folding cardboard plates with a view to forming packaging boxes, in which: said plates are arranged one against the other at a transit store; moving at least one movable gripping means in a forward stroke from a reception station to said store; said gripping means grips each plate individually at a gripping area; each gripped plate is transferred by displacement of said gripping means in a return extraction stroke from said store to the receiving station.

Such a method is characterized in that it further comprises at least the measurement of the position of said plate at least at its gripping zone; and adjusting said forward stroke as a function of said measured position.

According to additional, non-limiting characteristics, said treatment method can consist in increasing or decreasing the length of said outward stroke of the gripping means, as a function of said measured position.

Thus, by measuring the position of each plate at its gripping area, the invention makes it possible to correct the depth of the outward stroke, ensuring improved contacting of the gripping members on each plate.

Other characteristics and advantages of the invention will emerge from the detailed description which follows of nonlimiting embodiments of the invention, with reference to the appended figures in which:

- Figure 1 schematically shows a simplified view in vertical section of an example of a processing device, showing the movement of the gripping means according to the return stroke for extracting a plate from a transit store to the receiving station ; and

- Figure 2 schematically shows a detail view, similar to Figure 1, partially showing the displacement along the outward stroke, in particular highlighting the principle of measuring the position of the face of the plate located in front of the store, and the adjustment of the outward stroke of the gripping means.

The present invention relates to the treatment by folding of cardboard plates 1, in order to form packaging boxes.

Each plate 1 is intended to form a box. The plates 1, also called cutouts, can in particular be of the following two types:

of the “wrap around” type, that is to say that the box can be formed around the products to be packaged, or of the “American box” type, that is to say that the volume setting makes it possible to achieve all first a sheath, which sheath can then be filled with the products to be packaged and be closed.

Such plates 1 are arranged at a transit store 2. Several plates 1 are superimposed, in an adjoining fashion, the front of a plate 1 being situated against the back of an adjacent plate 1. These plates 1 rest at their lower edge on a transit surface 3. As can be seen in the embodiment of the figures, such a transit surface 3 is generally horizontal.

However, said transit surface 3 can also be provided inclined at a decreasing slope, from the rear of said magazine 2 where the plates 1 are loaded, towards the front where they are successively extracted, individually, one after the other.

Within the transit store 3, the plates 1 generally extend substantially vertically. In practice, the cardboard plates 1 can be slightly inclined and have a forward-facing angle of inclination ranging from ten to thirty degrees (from 10 to 30 °) relative to the vertical. Preferably, this angle ranges from ten to twenty degrees (from 10 to 20 °) and is in particular of the order of ten degrees (10 °).

It will be noted that suitable stops 4 can hold the plate 100 located at the front, retaining all of the other plates 1 grouped behind within said store 2.

Each plate 100 located at the front is transferred by means of at least one gripping means 5, capable of grasping a first plate 100 and of moving it from said transit store 2 to a reception station 6. A this level, the plate 1 is released and deposited, for processing, in particular by folding through a suitable station. Then, the gripping means 5 starts again in the opposite direction to grasp the next plate 1, which has moved towards the front of the transit magazine 2, to in turn become the first plate 100.

It will be noted that this movement of the plates 1 can be carried out by means of suitable means, ensuring their movement from the rear to the front of the transit store 2, for example via a conveyor. Said movement can also be carried out by pressing at the rear, as and when filling with new plates 1, or even naturally under the effect of gravity when said transit surface 3 is provided inclined. The displacement can also be obtained by a combination of one and / or the other of the abovementioned possibilities.

The gripping means 5 is provided movable, on the one hand, in a forward stroke from said receiving station 6 to the transit store 2 and, on the other hand, in the opposite direction, in a return stroke. This return stroke therefore consists in extracting the first plate 100 gripped by the gripping means 5 to take it out of the magazine 2 and then moving it towards the receiving station 6. The first plate 100 is therefore pulled from the front.

In addition, the actuation and movements of the gripping means or means 5 are provided for configurable. Therefore the mobility of the gripping means 5 can be managed by at least one servomotor.

In addition, said gripping means 5 can be mounted on a robot, in particular of the multi-axis robot type, allowing several degrees of freedom in the movements of said gripping means 5. In particular, as shown in the figures, said gripping means 5 can be mounted at one end of a multi-axial robot.

To do this, the gripping means is configured to grip a plate 1, namely the first plate 1 located at the front, at the level of a gripping zone 7. This particular gripping also makes it possible to release said plate 1 once arrived at said reception station 6.

Thus, each plate 1 comprises a gripping zone 7, that is to say a portion of the first plate 100 at the level of which the gripping means 5 grips it. In principle, such a zone 7 corresponds to a surface delimited from the front face of the first plate 100, that is to say the face oriented towards the receiving station 6.

It should be noted that the treatment device can comprise several distinct gripping means 5, in particular movable independently of each other, and for example each mounted at one end of a multi-axial robot. These gripping means 5 can be configured to grip a plate 1 together. The plate 1 can then comprise a single gripping zone 7 at the level of which the different gripping means 5 will position themselves to grip the plate 1 or then several zones of separate grips 7, for example one by grip means 5.

The plates 1 are generally deposited so that they extend horizontally at the receiving station 6. Preferably, the front face of a plate 1 located at the receiving station 6 is oriented downwards. A single plate 1 is in principle located at the reception station 6 simultaneously. In other words, the plate 1 located at the reception station 6 leaves this reception station 6 before it receives a new plate 1 brought in with the gripping means 5.

According to a particular configuration, said gripping means 5 comprises at least one member 8 for gripping by vacuum in contact with a face of each first plate 100, namely the face situated at the front. It will be noted that this front face may preferably constitute the bottom or one of the lateral faces of the box formed subsequently.

Preferably, the gripping means 5 comprises several members 8, in particular from two to eight. Each member 8 may be constituted by a suction cup, connected to a suitable pneumatic system, so that, on the one hand, once close to or in contact with the face of the first plate 1 to be gripped, perform a vacuum ensuring the maintaining said plate 1, making it integral with said gripping means 5, at a pressure sufficient to extract the first plate 100 by traction and to maintain it during its movement. On the other hand, once said plate 1 has been moved to the receiving station 6, the pneumatic system releases the vacuum, in particular by connecting the interior volume of each suction cup to atmospheric pressure, or even by injecting an overpressure therein, so as to release the plate 1 which is deposited at said receiving station 6.

Consequently, said gripping zone 7 comprises a contact surface of said at least one member 8 with each plate 1, in particular a surface where contact is made with each suction cup, with a view to operating the vacuum. This gripping area 7 is therefore delimited in relation to the number of members 8 and the location where they come to touch the front face of the first plate 1 to be gripped. In addition, a gripping zone 7 can be determined for each gripping means 5, in particular when the treatment device comprises several gripping means 5.

Advantageously, the invention consists in measuring the position of said plate 1 at least at the level of its gripping zone 7. Consequently, the position of the first plate 1 to be grasped is known exactly. This position is determined in real time, for each plate 1 when it is found first, at the front.

Further, the invention makes it possible to measure a single point, for example located in the center of the gripping area 7, or else to measure a set of scattered points, such as a cloud of points within said gripping area 7 .

To do this, the invention incorporates a means 9 for measuring the position of said plate 1 at least at its gripping zone 7, in particular of the first plate 100. Such a measuring means 9 may consist of at least one rangefinder, preferably a laser rangefinder. Several rangefinders can be used by the measuring means 9 to each measure at least one point and thus determine a position of the plate 1 within the gripping area 7.

The measured values for several points can be used in combination or combined, to obtain an average making it possible to determine the actual position of the first plate 100, as mentioned above.

Each point can also correspond to the place where each member 8 will come into contact with the front face of said first plate 100.

Therefore, regardless of the form that the first plate 100 takes, in particular a deformation in tiling, it is known exactly where said first plate 100 is located, at least at its gripping zone 7. In particular, the position of the first plate 100 can be offset from a theoretically ideal position 10, straight, shown in dotted lines in FIG. 2.

In general, the plates 1 are tiled so that they are curved towards the rear of the magazine 3. In other words, the plates 1 form a concavity, when they are observed from the reception station 6. Conversely , the N

plates 1 can also be convexly tiled. One or more plates 1 can also be offset laterally, or even slightly angularly turned.

Thus, the device 1 can make it possible to determine the actual position in the space of each first plate 100 at its gripping zone 7. When this position is offset from the theoretical position, the stroke of the gripping means 7 is adjusted in relation to the theoretical stroke.

In particular, once this actual position of the first plate 100 has been determined, the invention provides for adjusting the outward travel of the gripping means 5 as a function of said measured position. In other words, one can increase or decrease the length of the outward stroke of the gripping means 5, but also modulate one or more of its directions, in particular by means of the servomotor controlling the actuation of the movements of the multi robot. axis, to modify the trajectory of one or more of said members 8, so that they come into contact with the front face of the first plate 100, at its gripping zone 7.

In the example shown in Figure 2, the first plate 100 has a curved deformation, forming a concavity of its front face. The measurement of the position of one or more points within the gripping area 7 makes it possible to determine a position differential 11 between the theoretical position 10 and the real position detected. This differential 11 can result in a distance which can be passed on to increase the length and the forward stroke of the gripping means 5, which moves further until compensating for the distance corresponding to said differential 11.

Conversely, according to a case not shown, a possible convex deformation of the first plate 1, makes it possible to determine a differential 11 according to a distance which is removed from the length of the outward stroke of the gripping means 5.

In addition to any convex or concave deformations of the first plate 100, its gripping zone 7 can also be inclined relative to the position of the theoretical gripping zone 7. This results in a directional modification of the stroke of the gripping means 5.

The stroke adjustment can be automatically transmitted via the motor, in particular a servomotor, precisely controlling the movements of the gripping means 5, in particular of the robotic arm which supports it.

In the alternative, the outward stroke being adjusted, in the opposite direction, the return stroke is modified to bring the gripping means 5 back to its original position, removing the plate 1 entered at the reception station 6. Therefore , the invention can also ensure a rectification of a bad positioning of any plate 1 within the transit store 2, to deposit each plate 1 transported exactly at the right location at the receiving station 6, in a well-defined position, in particular by said initial position of the gripping means 5.

In addition, it is also possible, through said multi-axis robot, according to its degrees of freedom, to adjust the displacement of the gripping means 5, to adapt transversely to a difference in position of the first plate 100 , in addition to the longitudinal and / or angular adjustment of the outward stroke of said gripping means 5.

Consequently, the gripping means 5 and its members 8 come into perfect contact with the face of each first plate 100 at the time of its gripping, offering an improved application of the contact of said members 8, in particular suction cups, against the first plate 100 to transfer from transit store 2 to reception station 5.

Claims (7)

1. Device for processing by folding cardboard plates (1) in order to form packaging boxes, comprising: - a transit store (2) of said plates (1); - a receiving station (6) for folding said plates (1); - At least one mobile gripping means (5), on the one hand, according to a forward stroke from said receiving station (6) to the store (2) and, on the other hand, according to a return extraction stroke individual of each plate (1) cardboard from said shop (2) until position of reception (6), configured for grab a plate (1) to level one zone of grip (7) then release it; said treatment device being characterized in that it further comprises: - means for measuring (9) the position of said plate (1) at least at its gripping zone (7); a means for adjusting said outward stroke of said gripping means (5), as a function of said measured position. 2. Treatment device according to claim 1, characterized in that said measuring means (9) consists of at least one rangefinder, preferably a laser rangefinder. 3. Treatment device according to any one of the preceding claims, characterized in that said gripping means (5) comprises at least one member (8) for gripping by depression in contact with the gripping zone (7) of each plate (1). 4. Treatment device according to any one of the preceding claims, characterized in that the gripping means (5) is mounted on a robot, in particular of the multi-axis robot type. 5. Treatment device according to any one of the preceding claims, characterized in that the mobility of the gripping means (5) is managed by at least one servomotor. 6. Method of treatment by folding of cardboard plates (1) in order to form packaging boxes, in which: - said plates (1) are arranged one against the other at a transit store (2); - It moves at least one gripping means (5) movable in a forward stroke from a receiving station (6) to said store (2); - said gripping means (6) individually grips each plate (1) at a gripping zone (7); - Each plate (1) entered is transferred by displacement of said gripping means (5) in an extraction return stroke from said store (2) to the receiving station (6); characterized in that it further comprises at least: - measuring the position of said plate (1) at least at its gripping area (7); and - The adjustment of said outward travel as a function of said measured position. 7. Treatment method according to claim 6, characterized in that it consists in increasing or decreasing the length of said outward stroke of the gripping means (5), according to said measured position.