EP2931475B1 - Sanding device including means for changing a sanding disk - Google Patents

Description

TECHNICAL AREA

The present invention relates to the field of sanding devices.

More specifically, the present invention relates to a sanding device comprising means for precise and autonomous abrasive disk change.

More specifically, the invention applies in particular to orbital sanders having dust suction means through a support plate and through the abrasive disk.

STATE OF THE ART

Various sanding devices and means for changing their abrasive discs have already been proposed.

Examples of such known devices can be found in the documents FR 2 942 735 , US 5,231,803 and GB 2 352 417 .

PURPOSE OF THE INVENTION

A first object of the present invention is to provide means to ensure reliable operation over time, despite operating in a difficult environment because of the dust resulting from sanding.

Another object of the invention is to provide means for ensuring a precise relative positioning of a sanding support plate with respect to replacement abrasive discs intended to be placed on said support plate.

DESCRIPTION OF THE INVENTION

The aforementioned objects are achieved according to the present invention with a sanding assembly as defined in claim 1 attached.

QUICK DESCRIPTION OF THE FIGURES

• la figure 1 illustre une vue générale d'un ensemble de changement d'un disque abrasif perforé sur une ponceuse orbitale, conforme à la présente invention,
• la figure 2 illustre schématiquement la structure générale d'une ponceuse orbitale,
• les figures 3 et 4 illustrent respectivement un plateau conforme à la présente invention et un disque abrasif perforé destiné à être fixé sur un tel plateau,
• les figures 5 et 6 illustrent des moyens de pré-positionnement du plateau de la ponceuse orbitale au niveau de l'ensemble de changement de disque abrasif, à deux stades successifs de leur fonctionnement,
• la figure 7 illustre un sous ensemble d'orientation du plateau de la ponceuse orbitale,
• la figure 8 illustre un sous-ensemble d'arrachage d'un disque perforé, conforme à la présente invention,
• la figure 9 illustre un sous-ensemble de contrôle d'un disque perforé, conforme à la présente invention, et
• la figure 10 illustre un sous-ensemble de positionnement d'un disque perforé en regard du plateau support.

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of non-limiting example and in which:

• the figure 1 illustrates a general view of a change assembly of a perforated abrasive disc on an orbital sander, according to the present invention,
• the figure 2 schematically illustrates the general structure of an orbital sander,
• the Figures 3 and 4 respectively illustrate a plate according to the present invention and a perforated abrasive disk intended to be fixed on such a plate,
• the Figures 5 and 6 illustrate means for pre-positioning the orbital sander plate at the level of the abrasive disk change assembly, at two successive stages of their operation,
• the figure 7 illustrates a subset of orientation of the orbital sander plate,
• the figure 8 illustrates a subassembly for tearing off a perforated disc, according to the present invention,
• the figure 9 illustrates a subset of control of a perforated disk, according to the present invention, and
• the figure 10 illustrates a subset of positioning a perforated disk next to the support plate.

DETAILED DESCRIPTION OF THE INVENTION

We have shown on the figure 1 an assembly adapted to ensure the automatic change of perforated abrasive discs 10 placed on the support plate 110 of an orbital sander 100.

This set constitutes a complete and autonomous system allowing, after simple positioning of the orbital sanding effector
100 by an automated means, to angularly orient the plate 110 of the sander 100, to remove a used perforated disc 10, to position a new perforated disc 10 on the tray, to control at all times the presence or absence of disc perforated 10 on the plate 110 and store a set of new perforated discs 10 in a magazine. The system guarantees precise positioning of the new perforated disc 10 by imposing the coincidence of suction orifices respectively provided in the abrasive disk 10 and in the plate 110.

• Un système 200 d'indexage du plateau 110,
• Un système 300 d'ascenseur pour arrachage,
• Un système 400 d'arrachage de disque 10,
• Un système 500 de contrôle de la présence d'un disque 10,
• Un système 600 de magasin de disques neufs 10,
• Un système 700 d'ascenseur pour le magasin de disques neufs 10.

The abrasive disk change assembly illustrated on the figure 1 annexed comprises 6 subsets:

• A system 200 for indexing the plate 110,
• A lift system 300 for pulling off,
• A system 400 of disc tearing 10,
• A system 500 for checking the presence of a disk 10,
• A new disk store system 600 10,
• An elevator system 700 for the new record store 10.

The set illustrated on the figure 1 is designed to be compact enough to be embedded on a moving means or on the rail of a 7-axis industrial robot for example.

The aforementioned 6 subassemblies are positioned to intervene successively in order to tear off a used abrasive disk 10 placed on the plate 110 of an orbital sander 100, then to replace a new disk 10 on the plate 110, starting from a unique and constant position of the sander 100 (O, X, Z mark) and its automated arm. In the following description, this position of the sander will be called "single position" for simplification.

The respective position of each of the 6 subsets makes it possible to individually actuate each of these subsets sequentially without interfering with the other subsets.

The sander 100 is placed on an automated arm adapted to sequentially move the sander between the abrasive disc changing position 10 illustrated in FIG. figure 1 and a working position remote from the disk change assembly, wherein the abrasive disk carried by the plate 110 is supported on a piece to be sanded and drag to ensure the sanding of this piece.

The structure and operation of such an automated arm are known in themselves and can be the subject of many embodiments. The automated arm is not illustrated in the accompanying figures and will not be described in more detail later.

The orbital sander 100 schematized on the figure 2 has a housing 102 which carries a motor shaft 120 centered on an axis 122 and a driven shaft 130 connected to the plate 110 and itself centered on an axis 132 parallel to the axis 122 of the motor shaft 120 but eccentric with respect to this axis 122 of a few millimeters.

The drive shaft 120 is rotated about the axis 122 by the motor 140 of the sander. The driven shaft 130 is rotatably mounted in a bearing 136 connected to the drive shaft 120 by a rigid radial arm 134 transverse to the axis 122. Thus, when the drive shaft 120 is rotated about the axis 122 , the bearing 136 describes an orbital movement about the axis 122. The driven shaft 130 is continuously free to rotate in the bearing 136, about its axis 132. The relative rotational movement of the driven shaft 130 relative to the bearing 136 depends on the resistant forces applied by the sanded piece on the abrasive disc 10 connected to the plate 110.

When stopped, the motor shaft 120 becomes free and can be turned manually.

The support plate 110 is carried by the free end of the driven shaft 130 emerging from the housing 102. It extends perpendicularly to the axis 132. The plate 110 is adapted to receive and maintain by any appropriate means, for example by a velvet / hook type system or any equivalent means, an abrasive disk 10.

The plate 110 and the disc 10 are provided with respective through perforations 112, 12. The arrangement of the perforations 12 provided on the disc 10 is identical to the arrangement of the perforations 112 provided on the plate 110 to allow the evacuation of the dust by suction. course of operation. Each perforation 12 of the disc 10 must be perfectly aligned with a perforation 112 of the plate 110 to allow an optimal suction flow.

We have shown on Figures 3 and 4 12 perforations respectively in each disk 10 and in the tray 110. Of course the present invention is however not limited to this particular provision.

As previously indicated, according to the invention, the support plate 110 comprises two notches 114, 116 distributed angularly around its periphery. The two notches extend over the entire thickness of the plate 110 and opens onto the peripheral edge of the plate.

Preferably as seen on the figure 3 the two notches 114, 116 are symmetrical and diametrically opposed.

A first notch 114 is intended to cooperate with the positioning or indexing module 200 and the second notch 116 is intended to cooperate with a tear-off pliers 410 and the abrasive disk presence control module 500.

The inventors have found that the realization of indexing means on the plate 110 in the form of a removal of material at the level of the two symmetrical notches 114, 116, has no dynamic or vibratory impact on the orbital sander. rotation.

We will now describe the means 200 for positioning the free axis 130 of the plate 110, illustrated in FIGS. Figures 5 and 6 attached.

As we see on the figure 1 these means 200 are preferably placed in the upper part of the disc changing assembly, at the station occupied by the sander 100 in the tear-off position of a used disc and positioning of a new disc 10.

The presence of two free shafts 120, 130 complicates the setting in position of the plate 110 and therefore of its suction orifices 112, since the displacement of the casing 102 thanks to the automated arm does not make it possible to act directly on the position of the shaft 130, the latter can operate a free planet movement around the axis 122.

To satisfy this objective of positioning the plate 110, there is provided according to the invention a prepositioning station 210 illustrated on the Figures 5 and 6 having an inclined surface 212 and a precise angular orientation station 220 illustrated on the figure 7 comprising two rollers 222, 224, one of which is motorized.

The inclined surface 212 is located along a rectilinear section of the approach path of the plate 110 when the automated arm (not shown in the appended figures as indicated above) moves the sander 100 in the single position (reference O; X Z) that it must occupy in the set of disk change. However, the inclined surface 212 is not parallel to the main direction of this section, but converges towards the median plane of the trajectory of the plate, towards the aforementioned single position. In the remainder of the description, the aforementioned plan will be referred to as the "median plane of trajectory". This plan is parallel to the plan of figures 1 and 8 to 10 and perpendicular to the plane of Figures 5 to 7 .

Thus when the automated arm moves the sander 100 in the aforementioned single position, the periphery of the plate 110 comes into contact with the inclined surface 212. Thus the plate 110 tends to be braked and the shaft 130 of the plate 110 is oriented towards the rear of the direction of advance, relative to the motor shaft 120, as seen in the comparative examination of Figures 5 and 6 .

The two rollers 222 and 224 are carried by a mount 225 on either side of the median plane of trajectory of the plate 110. Their axes of rotation are parallel to the axes 122 and 132. Thus at the end of its displacement the plate 110 comes in contact with the two rollers 222 and 224 and the driven shaft 130 of the plate 110 ends to position itself precisely behind the motor shaft 120, the axis 132 and the axis 122 state in a plane which coincides with the direction axis of advance as seen on the figure 7 and which corresponds to the median plane of trajectory.

The motorized roller 222, in contact with the periphery of the plate 110, then makes it possible to drive in rotation the plate 110 around the axis 132 (and thus its perforated abrasive disk 10) in order to angularly orient the plate 110.

A sensor 226 preferably comprising a mechanical probe 227 located between the two rollers 222 and 224, in the median plane of trajectory, detects one of the two notches 114 of the plate 110 and triggers the rotational stop of the roller 222 when the probe 227 is placed opposite the notch 114, then ending the positioning of the suction ports 12 and 112. The detection of the notch 114 may be made in various ways, for example but not necessarily by penetration of the mechanical probe in the notch 114.

The orbital sander 100 then occupies the precise position sought with respect to the assemblies 300, 400, 500, 600 and 700 to ensure the removal of a used disk 10 and the installation of a new disk 10.

The disk peel subassembly 400 illustrated in FIG. figure 8 .

This pulling subset 400 associated with the elevator subassembly 300 is placed at rest laterally at a lower floor relative to the station occupied by the sander 100 in a single position.

The tearing subassembly 400 comprises a plate 410 which rotates a jaw 412. The plate 410 and the jaw 412 form in combination a disk gripping pliers. The jaw 412 can be moved by any appropriate means, for example a jack 414, between a rest position, as illustrated in FIG. figure 8 in which the jaw 412 is remote from the plate 410, for example orthogonal to the plate 410, the clamp is open, and a working position in which the jaw 412 is pressed against the upper surface of the plate 410 and the clamp is by consequently closed.

The elevator 300 may be the subject of many embodiments. It preferably comprises a guide 310 inclined with respect to the vertical and centered on the median plane of trajectory, associated with a jack 320. The guide 310 and the jack 320 are adapted to move the plate 410 and the lifting subassembly 400 in the median plane of trajectory between a retracted rest position shown on the figure 1 in which the pulling subassembly 400 is waiting in a lower lateral position relative to the sander 100 and a working position shown on the figure 8 in which the plate 410 is moved in abutment against the surface bottom of the plate 110, the jaw 412 being placed opposite the notch 116.

In this position, the actuation of the jack 414 causes the closure of the clamp by pivoting the jaw 412 (which is placed in the notch 116), and pinching the edge of a used disk 10 at the notch 116 .

The retraction of the jack 320 makes it possible to lower the plate 410 in the closed position of the clamp and thus to tear off the disk 10.

We will now describe the subassembly 500 for checking the presence or the absence of a disk opposite the figure 9 .

This control subassembly 500 is also placed at rest laterally at a lower stage relative to the station occupied by the sander 100 in a single position, and this preferably in a position diametrically opposed to the pulling module 400 with respect to the vertical of the sander 100.

The control module 500 comprises a rod 510 rotatably mounted on a base 512 and moved by any appropriate means, for example a jack 514, between a rest position, as illustrated in FIG. figure 9 in which the rod 510 is remote from the plate 110, and a working position in which the rod 510 is moved towards the plate 110 opposite the notch 116. During this movement, the rod 510 moves in the median plane of trajectory .

Those skilled in the art will understand that when a disk 10 is present on the plate 110, the end of the rod 510 abuts against the disk 10. On the other hand, in the absence of a disk 10, the rod 510 can engage in the notch 116. A detection of the amplitude of the stroke of the rod 510 therefore allows to control the absence or the presence of a disk 10 on the plate 110. This amplitude detection can be performed at using any appropriate means, for example a bulb type "Flexible Blades Switch" or "ILS".

Preferably, the control module 500 is actuated firstly after tearing off a used disc 10 in order to check that the pulling has taken place. well done and secondly after setting up a new disc to control that the establishment of this new record has been made.

This control step is essential to ensure that the plate 110 is not likely to be affixed to a part to be sanded, being devoid of abrasive disc 10. In the opposite case indeed the displacement of the plate 110 on said part to be sanded could to deteriorate it.

We will now describe the positioning module 600 of a disk 10 on the plate 110 and spare disk storage, illustrated on the figure 10 .

This subassembly 600 is placed under the station occupied by the sander 100 in a single position, in the vertical thereof.

After tearing off a used disc 10, a new disc 10 must be affixed against the platen 110. A magazine system 610 stores a set of abrasive discs 10 stacked horizontally on a base 602. The discs 10 are positioned by an operator on 2 vertical centering rods 612, 616 each equipped, at their upper free end with a clip 613, 617 for holding the abrasive discs 10 and at their lower end, with a return spring 614, 618.

The clips 613, 617 are adapted to allow the extraction of a disc 10 when it adheres to the plate 110 while prohibiting extraction of the underlying disc.

The centering rods 612, 616 are mounted to slide vertically on the base 602 and urged downwards by the springs 614, 618 relative to the base 602.

At the request of a control system, an elevator system 700, for example a cylinder 710 underlying the magazine 610, makes it possible to push the magazine 610 upwards and to propose to the plate 110 without a disk a new tool 10 .

The angular orientation of the new disk 10 relative to the plate 110 and therefore a perfect alignment of the respective perforations 12 and 112 provided on the disk 10 and on the plate 110 are guaranteed since the plate is positioned accurately with respect to the sensor 226 and the The 610 store itself is precisely oriented with respect to the 226 sensor repository.

After contact of the abrasive disk 10 present on the top of the reserve in the magazine 610, with the attachment system provided on the lower surface of the plate 110, for example a velvet / hook type system as indicated above, the descent of the store 610 by controlling the cylinder 710 separates the disk 10 from the reserve 610.

As mentioned above once a new disc 10 deposited under the plate 110 of the sander 100, the control system 500 ensures the presence of the disc 10 by the previously described step of displacement of the rod 510 and measurement of the stroke of it.

The abrasive disk change assembly then allows the automated arm to remove the orbital sander 100 to continue its sanding operation.

Alternatively the device according to the present invention may comprise an additional actuator of the slide type to provide several abrasive disc magazines 610 with different particle sizes, for example, selectively under the plate 110 of the sander 100.

ADVANTAGES OF THE INVENTION

The operation of surface preparation by orbital sanding is more and more automated on repetitive tasks, especially by industrial robots. Whether for the production of large parts in small series or the production of smaller parts in mass production, the automation of these manual tasks represents many interests: in particular to relieve the operators of the risks of musculoskeletal disorders or industrial hygiene (dust, noise ...) and help to increase productivity.

The assembly proposed according to the invention allows complete automation of the abrasive disc change and ensures precise positioning of the abrasive discs on the support plate of the sanding device suitable for ensuring optimum suction of sanded dust and to prohibit the application of the tray sanding support without the presence of a disc abrasive, on a surface to be sanded, thus avoiding any risk of deterioration of the surface to be sanded.

• il constitue un changeur de disques abrasifs autonome et compact, par le positionnement de ces éléments constitutifs,
• il permet en particulier un procédé d'abrasion orbitale aléatoire avec disques perforés,
• il permet par la présence d'encoches symétriques d'indexage d'éviter toute perturbation dynamique par rapport à des solutions connues de l'art antérieur conduisant à des phénomènes vibratoires néfastes,
• il autorise des changements nombreux de disques abrasifs permettant un ponçage de pièces de grandes dimensions (par exemple et non exclusivement dans les domaines nautique, éolien ou aéronautique).

The assembly according to the present invention is furthermore remarkable for the following points:

• it constitutes an autonomous and compact abrasive disc changer, by the positioning of these constituent elements,
• it allows in particular a random orbital abrasion process with perforated discs,
• it makes it possible, by the presence of symmetrical indexing notches, to avoid any dynamic perturbation compared to solutions known from the prior art, leading to harmful vibration phenomena,
• it allows numerous changes of abrasive discs allowing the sanding of large parts (for example and not exclusively in the nautical, wind or aeronautical fields).

Claims (9)

1. Sanding assembly comprising a sanding device (100) comprising a plate (110) for supporting a sanding disk (10) and motor-driven means (140) suitable for moving the supporting plate (110), characterised by the fact that the supporting plate (110) comprises two notches (114, 116) distributed angularly along the periphery thereof, a first notch (114) for engaging with a positioning module (200) and a second notch (116) for engaging with a pulling jaw (400) and a module (500) for verifying the presence of the sanding disk, and characterised in that the assembly comprises 6 sub-assemblies: a system (200) for indexing the plate (110), a lift system (300) for pulling, a system (400) for pulling the disk (10), a system (500) for verifying the presence of a disc (10), a system (600) of a magazine of new disks (10), a lift system (700) for the magazine of new disks (10).
2. Assembly according to claim 1, characterised in that the sanding device (100) is an orbital sander having a crankcase (102) which carries a drive shaft (120) centred on an axis (122) and a driven shaft (130) linked to the plate (110) and itself centred on an axis (132) parallel to the axis (122) of the drive shaft (120) but off-centred in relation to this axis (122) by a few millimetres, with the driven shaft (130) being mounted to rotate freely in a bearing (136) linked to the drive shaft (120) by a radial rigid arm (134) transversal to the axis (122) of the drive shaft.
3. Assembly according to one of claims 1 or 2, characterised in that the plate (110) and the disk (10) are provided with respective through perforations (112, 12) of identical arrangement.
4. Assembly according to one of claims 1 to 3, characterised in that the two notches (114, 116) are symmetrical and diametrically opposite on the plate (110).
5. Assembly according to one of claims 1 to 4, characterised in that the means (200) for prepositioning the plate (110) comprise an inclined surface (212) located along a straight section of the approach path of the plate (110) in such a way that the periphery of the plate (110) comes into contact with the inclined surface (212).
6. Assembly according to one of claims 1 to 5, characterised in that means for orientation of the plate (110) comprise two rollers (222, 224) carried by a frame (225) on either side of the median plane of the path of the plate (110), with one of the rollers being motor driven and associated with a sensor (226) comprising a mechanical probe (227), suitable for detecting one of the two notches (114) of the plate (110).
7. Assembly according to one of claims 1 to 6, characterised in that it comprises a sub-assembly for pulling (400) comprising a motor-driven jaw (410, 412) for grasping a disk and a cylinder (414) suitable for moving the jaw between an idle position separated from the sander and a working position in which the jaw is placed across from a notch (116).
8. Assembly according to one of claims 1 to 7, characterised in that it comprises a sub-assembly (500) for verifying the presence or the absence of a disk comprising a rod (510) mounted to rotate on a base (512) and moved by a cylinder (514), between a retracted idle position and a working position wherein the rod (510) is moved towards the plate (110) across from a notch (116).
9. Assembly according to one of claims 1 to 8, characterised in that it comprises a sub-assembly for pulling (400) comprising a pulling jaw (410, 412) guided in movement in the median plane of the path and a sub-assembly (500) for verifying the presence or the absence of a disk comprising a rod for detecting (510) guided in movement in a median plane of the path, with the sub-assembly for pulling (400) and the sub-assembly (500) for verifying being substantially diametrically opposite with respect to the vertical axis of the sanding device (100) and characterised by the fact that it further comprises a system (600) of a magazine of new disks (10) associated with an underlying lift system (700) to the sanding device (100) to the vertical of the latter.

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