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(11) | EP 3 050 642 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | DEVICE FOR CLEANING ROLLERS |
| (57) The invention relates to a device for cleaning rollers onto which glue has become
adhered. The robotic arm (2) incorporating the roller (1) is adjusted via a drive
element (3) that is fixed to an electric motor (7) such that when the motor (7) is
actuated, the roller (1) moves. A cleaning motor (7'), which rotates in the same direction
as said drive motor (7), is connected to a felt disc (6) that is continuously moistened
with solvent supplied by an ejector (8). The cleaning motor (7) is arranged such that
the edge of the felt disc (6) remains in contact with the edge of the roller. When
both motors (7, 7') are actuated, the felt disc (6) cleans the roller (1) by means
of friction. |
OBJECT OF THE INVENTION
[0001] The present invention refers to a device for cleaning rollers of the kind used in machinery for clamping metal plates.
[0002] It is of particular use in the automotive industry and the industry of assembling metal plates.
TECHNICAL PROBLEM TO ADDRESS AND BACKGROUND OF THE INVENTION
[0003] Clamping or hemming is known as the mechanical process that joins two plates together by folding the edge of one of them over the other.
[0004] It is the process normally used for the outer parts of vehicles, which are comprised basically of a visible outer panel and an inner panel that is usually hidden from sight.
[0006] Clamping is not a structural way of joining parts together, and there are additional methods used in order to prevent the inner panel from sliding in relation to the outer panel. One of these methods is combining clamping with the application of adhesives.
[0007] The clamping process by means of applying adhesives is performed in basically 3 phases. In the first phase, a bead of glue is applied on the outer panel about to be clamped. Afterwards, the outer and inner panels are assembled together. In the final phase, the plates are clamped together.
[0008] During the clamping process, when the plates are joined together, the glue spreads along the gaps between the two panels, and can sometimes spread to the outside of the panels.
[0009] There are different techniques to perform the clamping procedure. One of them is roller clamping.
[0010] Using this technology, a robot rolls a metal wheel, the roller, over the outer edge of the part that will be folded over the other part, so that as the roller advances it folds the plate.
[0011] At the same time the plate is being folded, the glue is compressed and spread all along the length and width of the two plates being joined together. As mentioned above, when the glue spreads, it can sometimes spread to the outside of the panels. This would not be a problem so long as the glue remains jutting out of the union of the two plates. However, one of the usual problems is that the glue can spread out in a large proportion, making contact with the wearing face of the roller.
[0012] A rolling tool that is dirty with clamping glue is not acceptable, since as it advances, it will stain the folded flange and will later cause problems to the paint, since the remains of glue will cause a deficient adherence.
[0013] Although the area where the glue juts out from between the two plates is afterwards sealed with a cosmetic resin, the flat side where the roller runs does not receive the same treatment, meaning that a dirty roller could cause the paint to peel away, and this would cause both quality and aesthetic problems, such as those related to rusting.
[0014] Nowadays the process of cleaning the roller is based on making the roller rotate against another element in order to eliminate the remainders of glue by means of friction.
[0015] In this procedure, the first difficulty encountered is making the roller rotate since the roller rotates freely while it works, moving by force of friction against the piece being clamped, and therefore does not move of its own accord.
[0016] Every system for cleaning rollers incorporates some kind of external equipment that can be attached to the roller and that is in charge of making it roll.
[0017] As for the friction system, two different systems are known:
- 1. Making the roller rotate against a fixed component like a strip, so that the edge of said strip brushes against the wearing surface of the roller, such that the glue is transferred from the roller to the strip.
- 2. Removing the roller from its attachment to the robot and inserting it in a washing tank.
[0018] The first method has the problem that the strip used starts accumulating resin, so that in a few cycles it is no longer useful and must be replaced. In order to reduce as much as possible the time required to replace the strip, this process needs to be automatized, so that there must be a facility to feed the strip that is in charge of feeding the cleaning area and a station to cut the strip, so that as the cleaning of the strip is finished, it moves forward and the dirty stretch of strip can be cut and removed. The facility is complex and therefore financially unappealing.
[0019] The second method requires a system to only detach the roller quickly, which can involve delicate mechanisms that afterwards need to bear stresses.
[0020] The present invention addresses the problems described above and which have not been solved in the present state of the art, simplifying the current process and making the cleaning of rollers a very affordable process.
DESCRIPTION OF THE INVENTION
[0021] The present invention represents a device for cleaning rollers that comprises a drive motor, a drive element joined to said drive motor, which incorporates at least one lug on its base, a felt disc joined to a cleaning motor and a solvent ejector connected to a solvent tank, which is in charge of applying solvent to the felt disc and of keeping it moistened during the working process.
[0022] The drive motor refers to the motor in charge of moving the drive element, and the cleaning motor refers to the motor in charge of moving the felt disc in charge of cleaning the roller, both motors being of the kind known in the state of the art.
[0023] The roller comprises at least one opening on the base, which is aligned with the corresponding fixing lugs. The lugs are located on the drive element, which are cylindrical and capable of axial movement along the openings located on the drive element.
[0024] One of the ends of each lug is connected to the drive element by means of a spring, while in the other end the lug juts out of the drive element, sticking out. This way, the lugs have axial movement. They retreat until they are housed entirely inside the drive element when they are compressed, and they expand until they stick out of the drive element up to a certain length when they stop exerting pressure on the springs.
[0025] A tool assembly for a robot, which contains the roller about to be cleaned, places the base of the roller so that the openings located on the base of the roller are aligned with the corresponding lugs of the drive element.
[0026] The cleaning motor rotates in the same direction as the drive motor. In this way, in the area where the felt disc makes contact with the roller, both speeds add up causing the felt disc to clean the roller by means of friction.
[0027] The base of the roller incorporates a series of openings placed in correspondence with the lugs of the drive element, and with slightly bigger dimensions in order to easily house them. In the moment when the roller is about to couple with the drive element, both components are positioned in such a way that their rotation axes coincide. Initially, the lugs will not coincide with the openings of the roller, so that the base of the roller will act on the lugs and compress them, pressing on the springs with the other end of the lugs and housing them inside the drive element. By actuating the drive motor, the drive element starts rotating until it reaches a position in which the fixing lugs meet the openings on the base of the roller, fitting inside them, expanding by means of the springs and transmitting the movement of the drive motor to the roller.
[0028] The device comprises a positioning plate that has two parallel slots and that is rigidly mounted to the cleaning motor. It also incorporates a fixing mount that comprises through holes in correspondence with the parallel slots of the positioning plate. In this way, a series of screws go through the fixing mount via the through holes and the positioning plate via the parallel slots, allowing the positioning plate to move linearly along the length of the parallel slots.
[0029] The final position of the positioning plate is fixed by means of nuts coupled to the screws. In this way, the felt disc is positioned in correspondence with the roller meant to be cleaned.
[0030] The fixing mount can be fixed in different working positions depending on whether the felt disc needs to clean conical or cylindrical rollers.
[0031] In order to maintain optimal working conditions, the ejector applies a solvent on the felt disc to keep it continuously moistened.
BRIEF DESCRIPTION OF THE FIGURES
[0032] To complete the invention being described, and in order to help to a better understanding of the features of the invention, according to a preferred embodiment thereof, a set of drawings is accompanied, in which the figures described below have been represented, for purely illustrative purposes and should not be construed as limiting:
Figure 1 a shows a perspective view of the drive element of the roller in a first embodiment with the electric motor actuating it, together with an enlarged exploded view of the drive element.
Figure 1b shows a perspective view of the drive element of the roller in a second embodiment with the electric motor actuating it, together with an enlarged exploded view of the drive element.
Figure 2 shows a perspective view of the cleaning equipment.
Figure 3 shows a perspective view of the roller tool assembly for a robot.
Figure 4 shows a perspective view of the device in which the constituent components are represented.
Figure 5a shows a perspective view of the complete device with a protective housing in an open position.
Figure 5b shows a perspective view of the complete device with a protective housing in a closed position.
[0033] Provided below is a list of the references used in the figures:
1. Roller.
2. Roller tool assembly for a robot.
3. Multiple drive element of the roller.
3'. Simple drive element of the roller.
4. Circular fixing lug.
4'. Polygonal fixing lug.
5. Spring.
6. Felt disc.
7. Drive motor.
7'. Cleaning motor.
8. Solvent ejector.
9. Electric box.
10. Solvent tank.
11. Fixing mount.
12. Positioning plate.
13. Parallel slots.
14. Protective housing.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0034] The present invention refers to a device for cleaning rollers (1) used in the process of clamping plates in a fast, simple and affordable way.
[0035] Figure 1 a shows a drive motor (7) together with a multiple drive element (3) where the roller (1) is fixed, and a series of circular fixing lugs (4). The multiple drive element (3) is also shown in an enlarged exploded view so that the inner components are visible, such as the circular fixing lugs (4) and some springs (5).
[0036] Figure 1b shows, in a second embodiment, a drive motor (7) together with a single drive element (3') where the roller (1) is fixed, and a polygonal fixing lug (4'). The single drive element (3') is also shown in an enlarged sectional view so that the inner components are visible, such as the polygonal fixing lug (4) and a spring (5).
[0037] It must be highlighted that the circular (4) and polygonal (4') lugs are really cylindrical lugs with a circular or polygonal transverse section, respectively.
[0039] Figure 2 shows the cleaning equipment comprising a cleaning motor (7') fixed to a positioning plate (12) with two parallel slots (13), a fixing mount (11), a felt disc (6) installed on the cleaning motor (7') and a solvent ejector (8) connected to a solvent tank (10). A series of screws are inserted in the fixing mount (11), which go through the parallel slots (13) and secure the positioning plate (12) to the fixing mount (11) in the desired position by means of screws. This position may be modified along the length of the parallel slots (13) depending on the size of the roller (1). Similarly, the position of the cleaning equipment can be modified such that it can be used to clean rollers (1) shaped like cones or cylinders.
[0041] All these figures include the solvent tank (10), the electric box (9) and the structure to support the entire device, keeping the components in their relative position so that it is easier to understand figure 4 with all the components installed.
[0042] Figures 5a and 5b include the protective housing (14) against splatters, which surrounds the entire device, in the open and closed positions respectively.
[0043] The roller (1), without being disassembled from the roller tool assembly for a robot (2) that incorporates it, is fixed to the drive element (3, 3') of the drive motor (7). For that, the drive element (3, 3') comprises at least a lug (4, 4') joined to a spring (5) on one of its ends that allows it to have axial movement, with the other end sticking out of the drive element (3, 3'). The roller (1) incorporates on its base a series of openings where said lugs are inserted (4, 4').
[0044] These openings preferably have, in the first embodiment, an elongated circular shape so that it is easier and faster to adjust the circular lugs (4) therein, which, as their name implies, have a geometry with circular transverse section.
[0045] In a second embodiment, the polygonal lug (4') has a geometry whose transverse section is such that when its fits into the corresponding complementary opening located on the roller (1), it does not slide and it can transmit the rotation of the drive motor (7) to the roller (1). This means that the polygonal lug can feature a traverse section of the lug in any geometry that is not circular, although a section that comprises sides will be chosen in order to provide a better grip, preferably a regular polygonal shape in order to make it easier to fit in the corresponding opening. In this second embodiment, the opening is located on the centre of the roller and has a geometry with the same transverse section as the polygonal lug (4'), with slightly larger dimensions in order to make adjusting easier. In a preferred embodiment, as shown in figure 1b, the transverse section has a hexagonal shape.
[0046] By means of the tool assembly (2) containing the roller (1), the roller (1) is positioned so that the base is secured to the drive element (3, 3'). The lugs (4, 4') of the drive element (3, 3') will not normally coincide with the openings of the roller (1) such that, when the roller (1) is fastened, the lugs (4, 4') will retract into the drive element (3, 3'), making the springs (5) compress.
[0047] Once the roller has been secured (1) to the drive element (3, 3'), the drive motor (7) is actuated, making the drive element (3, 3') rotate. The lugs (4, 4') are retracted into the drive element (3, 3') and pressing against the base of the roller (1) due to the force of the springs (5).
[0048] In the first embodiment of the invention shown in figure 1a, when the multiple drive element (3) rotates, said circular lugs (4) meet the openings included in the base of the roller (1), being inserted into said openings.
[0049] In the second embodiment of the invention shown in figure 2b, when the single drive element (3') rotates, the geometry of the polygonal lug (4') meets the geometry of the opening included in the centre of the roller (1), being inserted into said opening.
[0050] In either of the two cases, once the lugs (4, 4') are inserted into the openings of the roller (1), the rotating movement is transmitted to the roller (1), which is already connected to the drive motor (7).
[0051] The process of cleaning the roller (1) consists of putting the edge of the roller (1) in contact with the edge of the felt disc (6) such that, by means of friction, the dirt of the roller (1) is eliminated. The width of the felt disc (6) will always be greater or equal to that of the roller (1), ensuring that the entire width of the roller (1) makes contact with the felt disc (6).
[0052] The second embodiment, in which a simple cylindrical drive element (3') of a very small radius to length ratio is used, allows the cleaning equipment to move such that the felt disc (6) can attack the roller (1) not only on its front side, but also on the rims. This is also achieved by securing the roller (1) to the head of the simple drive element (3'), which only takes up the centre of the roller (1), and not of its entire base, as is the case in the first embodiment.
[0053] The cleaning motor (7') and the drive motor (7) of the roller (1) rotate in the same direction. In this way, the relative speed in the area of contact between the roller (1) and the felt disc (6) is the sum of the two speeds of the wheels at the points of contact, which allows the felt disc (6) to clean by means of friction at a higher efficacy.
[0054] In addition to the felt disc (6) there is an ejector (8) coupled to a solvent tank (10). In this way, the felt disc (6) is continuously moistened with solvent supplied by the ejector (8), which is in charge of applying the solvent on the felt disc (6). In this way, thanks to the solvent and the friction, it is easy to remove the adhesive adhered to the surface of the roller (1).
[0055] A conical roller (1) is the roller chosen in the device represented in the drawings. In the case when the roller was cylindrical instead of conical, the cleaning equipment would be moved so that the axes of the drive motor (7) and the cleaning motor (7') were parallel to each other, which would thus allow the cleaning of the cylindrical roller (1).
[0056] The cleaning motor (7') actuating the felt disc (6) is rigidly joined to a positioning plate (12) comprising a pair of parallel slots (13). The positioning plate (12) is attached to a fixing mount (11) that is rigidly joined to the workbench. This fixing mount (11) comprises drill-holes in correspondence with the parallel slots (13). In order to fix the position of the felt disc (6) in relation to the roller (1), a series of screws go through the fixing mount (11) and the parallel slots (13), enabling the positioning plate (12) to move along the parallel slots (13) until the desired position is found. The final position is fixed by applying nuts to the screws and thus fixing the positioning plate (12) to the fixing mount (11).
[0057] The cleaning device comprises a protective housing (14) that encloses the assembly in order to avoid splashes, since a large part of the adhesive and the solvent will be ejected outwards by action of the centrifugal force and, due to the rotating speed of the motors (7, 7'), it may be dangerous.
[0058] With this device, the roller (1) may be cleaned without having to disassemble it from the tool assembly for a robot (2) in which it is installed. The device also has reduced dimensions, which makes it easy to install it close to the clamping facility.
1. A device for cleaning rollers characterized in that it comprises:
- a drive motor (7),
- a drive element (3, 3') that incorporates at least one fixing lug (4, 4') on its base, joined to the drive motor (7),
- a cleaning motor (7'),
- a felt disc (6) joined to the cleaning motor (7'),
- a solvent ejector (8),
wherein- the roller (1) comprises at least one opening on the base that is aligned with the corresponding fixing lugs (4, 4'),
- a tool assembly for a robot (2) that contains the roller (1), positions the roller (1) so that the openings located on the base of the roller (1) are aligned with the corresponding lugs (4, 4') of the drive element (3, 3'),
- the cleaning motor (7') rotates in the same direction as the drive motor (7) so that, in the area where the felt disc (6) makes contact with the roller (1), both speeds add up, causing the felt disc (6) to clean the roller (1) by means of friction.
so that, by actuating the drive motor (7), the fixing lugs (4, 4') of the drive element (3, 3') fit into the openings of the roller (1), transmitting the movement of the drive motor (7) to the roller (1).2. A device for cleaning rollers according to claim 1, characterized in that one of the ends of the fixing lugs (4, 4') is joined by means of springs (5) to the
drive element (3, 3'), so that when the base of the roller (1) is positioned over
the drive element (3, 3'), the lugs (4, 4') retract until as they rotate, due to the
actuation of the drive motor (7), the fixing lugs (4, 4') meet the openings on the
roller (1) and fit inside them, expanding by means of the aforementioned springs (5)
in order to fix the roller (1) to the drive element (3, 3').
3. A device for cleaning rollers according to claim 1, characterized in that it comprises:
- a positioning plate (12) that comprises two parallel slots (13) and that is rigidly joined to the cleaning motor (7'), and
- a fixing mount (11) that comprises through holes in correspondence with the parallel slots (13) of the positioning plate (12),
so that a series of screws go through the fixing mount (11) via the openings and the positioning plate (12) via the parallel slots (13), allowing the positioning plate (12) to move linearly along the length of the parallel slots (13) and to secure, by means of nuts, the final position of the positioning plate (12), and to therefore secure the felt disc (6) such that it is positioned in correspondence with the roller (1) meant to be cleaned.4. A device for cleaning rollers according to claim 1, characterized in that the ejector (8) applies a solvent on the felt disc (6) in order to keep it continuously
moistened.
5. A device for cleaning rollers according to claim 3, characterized in that the fixing mount (11) has different working positions depending on whether the felt
disc (6) has to clean conical or cylindrical rollers (1).